摘要 |
<p>A method of deinking printed paper comprises pulping the paper to form an aqueous slurry, adding a deinking additive to the paper, and removing detached ink by flotation, wherein the additive comprises an organo-modified siloxane comprising units of the formula: [R1aZbSiO(4-a-b)/2]n in which each R1 is independently selected from a hydrogen atom, an alkyl, aryl, alkenyl, aralkyl, alkaryl, alkoxy, alkanoyloxy, hydroxyl, ester or ether group; each Z is independently selected from an alkyl group substituted with an amine, amide, carboxyl, ester, or epoxy group, or a group -R2- (OCPH2P) q (OCrH2r) S-R3; n is an integer greater than 1; a and b are independently 0, 1, 2 or 3; R2 is an alkylene group or a direct bond; R3 is a group as defined for R1 or Z above; p and r are independently an integer from 1 to 6; q and s are independently 0 or an integer such that 1 <= q + s >= 400; and wherein each molecule of the organo-modified siloxane contains at least one group Z.</p> |