Method for tagging thermoplastic materials with near infrared fluorophores
US5703229A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 29, 1996 |
| Grant date | Dec 30, 1997 |
| Priority date | — |
| Expiry date | Feb 29, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/62
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Provided are new compounds useful as near infrared fluorophoric markers. In the practice of this invention a method is also provided for tagging thermoplastic containers using near infrared fluorescing compounds or copolymerized residues readily capable of detection. The new compounds are phthalocyanine and naphthalocyanine derivatives which are covalently bonded to substituted silicon and aluminum compounds. The methods, compositions, and compounds described herein 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.