To obtain an ink-removing agent capable of separating ink from paper and preventing the reattachment of the ink and further bleaching colored fibers of the waste paper by adding the agent in a disintegration process of waste paper of telephone books colored in yellow.
This ink-removing agent is prepared by compounding 20-60wt.% of hydrosulfite, 20-60wt.% of a lower monovalent alcohol such as methanol, 10-30wt.% of a polyhydric alcohol such as glycerol and 1-5wt.% of an anionic surfactant. The ink-removing agent is added at 1-5wt.% based on water when waste paper of telephone books colored in yellow is disintegrated in an aqueous system after cut into adequate sizes. The printing component such as a printing ink is separated from paper by the action of the lower monovalent alcohol and the polyhydric alcohol; the printing component is held in water and the reattachment of the component is prevented by the action of both the alcohols and the surfactant; and the waste paper colored in yellow is bleached by hydrosulfite.
MATSUZAKI TOMIYA
YOSHIKAWA NOBUHIRO
OGASAWARA MASARU
KASAI SHIZUO
YOSHIMURA SHIGETAKA
YAMAMOTO KANTARO
