DEINKING COMPOSITION FOR FLOTATION AND DEINKING METHOD

摘要

A deinking composition for regeneration of waste paper by flotation comprises 99.7 to 97% by weight of a mixture which comprises monoalkyl ethers of ethylene oxide/propylene oxide copolymers represented by the following general formulas (A) and (B) and the mixing ratio of the compound (A) to the compound (B) ranges from 10: 90 to 90:10 (weight ratio); and about 0.3 to about 3.0% by weight of a polyoxyalkylene oxide selected from the group consisting of polyethylene oxides, polypropylene oxide and ethylene oxide/propylene oxide copolymers: R1 O - (PO)n 1 - ~(EO)m ~ (PO) n2~ - H ~ (A) R2 O - (EO) m 1 - ~ (EO) m 2 ~ (PO) n ~ - H . . . . .. (g) wherein m/(n1 + n2) ranges .from 0.5 to 1.5; (m1 + m2)/n ranges from 1.1 to 2.0; EO and PO represent ethylene oxide and propylene oxide units respectively; and the EO and PO in the brackets may be in either a random or block configuration. The deinking composition exhibits excellent deinking properties. Therefore, the use of the deinking composition in the flotation method makes it possible to prepare high quality regenerated pulp, for paper-making, having a high brightness and a low content of remaining ink.