Toshiba Corporation has announced a prototype ink that can be decolored by heat or solvent treatment that would eliminate the need for flotation cells in the deinking process during paper recycling. The new ink is expected to be most practical for use in laser printers, ink-jet printers, thermal printers, ball-point pens and writing ink. The prototype ink contains leuco dye, capsulized phenolic developer and a decoloring agent. Exposure to 180 degree C. heat or particular solvents will cause the chemical bonding of the dye and developer to break down. The developer then links with the decolorant to stabilized decoloration. This ink has the potential to reduce the deinking cost by 70 to 80 percent, but there are a number of challenges ahead for this prototype. Without a complete conversion, paper recyclers will still need to maintain a flotation cell system. There is also the challenge of segregating papers which have decolorable ink from other papers, and there is potential concern about solvent usage as an option to decolor the ink.

Source: Waste Age’s Recycling Times, October 19, pp. 3-4
Author: Ernesto Yermoli