Patent · US Expired

Recovery of raw materials from magnetic recording media

US6129847A · kind A · utility

6Cited by

2References

7Claims

0Family size

Assignee

BASF Magnetics GmbH · DE

Inventors

Thomas Wunsch · Speyer, DE
Karl-Heinz Sartor · Schwanau, DE
Axel Schulze · Darmstadt, DE
Norbert Muller · Tamm, DE
Jochen Eicher · Monsheim, DE
Oskar Stephan · Hockenheim, DE

Key dates

Filing date	Sep 9, 1996
Grant date	Oct 10, 2000
Priority date	—
Expiry date	Sep 9, 2016

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY02W30/62
WIPO fieldOther special machines
WIPO sectorMechanical engineering

Abstract

Magnetic powder and substrate material are separately recovered from finely chopped wastes of magnetic recording media consisting of a polymeric substrate and a magnetic layer present thereon in which finely divided magnetic powder is dispersed in crosslinked or uncrosslinked polymeric binder by treating the finely chopped wastes of magnetic recording media in a solution consisting of the potassium salt of a polyunsaturated fatty acid, or a biodegradable cleaning agent comprising phosphates, surfactants and a complexing agent, and one or more organic solvents or water while being subjected to mechanical action, and separately removing the magnetic powder from the substrate material by washing or sedimentation or in a magnetic separator.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.