Deinking waste electrophotography copy paper
US4276118A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 9, 1979 |
| Grant date | Jun 30, 1981 |
| Priority date | — |
| Expiry date | Oct 9, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/64
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The toners used for printing in the electrophotography processes such as xerography or laser printing are removed from copy paper. In the process, the paper is pulped to form an aqueous slurry. The toner is removed from the paper with a dual system of a collector and a collecting chemical. The best collectors have solubility parameters similar to the toners so that the softened toner is slightly soluble in the collector. These include polystyrene, polyvinyl chloride and polyacrylates, e.g., polymethyl methacrylates. Other collectors which are operable but less satisfactory are polyurethane and polypropylene. The collector is in the form of prills, beads or sheets. The specific collector will depend upon the specific chemicals in the toner. There are a number of requirements for the collecting chemical. It should be substantially insoluble in water. It should have a melting point that is at or below the approximate softening point of the toner or collector. It should be a saturated aliphatic primary alcohol, a mixture of such alcohols, an unsaturated aliphatic primary alcohol, a mixture of such unsaturated alcohols, a saturated secondary alcohol, a saturated aliphatic primary hydroc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.