Method for tagging thermoplastic materials with near infrared fluorophores
US5461136A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1994 |
| Grant date | Oct 24, 1995 |
| Priority date | — |
| Expiry date | Jun 27, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/62
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Provided is a method for tagging thermoplastic containers using near infrared fluorescing compounds or copolymerized residues readily capable of detection. Also provided is a method for identifying a thermoplastic container. Also provided are thermoplastic polymer compositions comprised of the near infrared fluorescing compounds or residues and articles comprised of such compositions. Also provided are new compounds useful as near infrared fluorophoric markers in the practice of this invention. The methods, compositions, and compounds of the present invention thus provide a total system useful for marking, for identification purposes, the various classes of thermoplastic wastes, so that they can be identified, sorted, and subsequently recycled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.