Process for separating polyamide from colorant
US6036726A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 1998 |
| Grant date | Mar 14, 2000 |
| Priority date | — |
| Expiry date | Feb 6, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/62
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for recycling colored polyamide material comprises the steps of (a) contacting solid colored polyamide material with an organic solvent composition at a temperature effective to dissolve the polyamide, thereby forming a solution containing colorant and dissolved polyamide; and (b) separating colorant from the polyamide. The process can optionally further comprise the step of recovering the colorant, recovering the polyamide, or recovering both the polymer and colorant. The organic solvent composition preferably is selected from the group consisting of aliphatic and aromatic ketones, aliphatic and aromatic alcohols, diols, water, and combinations thereof. Solvent compositions comprising at least one alcohol selected from the group consisting of butanediol, butanol, ethanol, and benzyl alcohol are preferred, such as aqueous solutions of 1-butanol or ethanol.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.