| 摘要 |
PURPOSE:To obtain an alumina carrier having such excellent properties that it can adsorb an org. dye to allow the dye to be enclosed therein, its pores can be sealed and it absorbs less visible light, by treating an aq. suspension of porous intermediate alumina with an acid and drying or firing it. CONSTITUTION:An aq. dispersion of porous intermediate alumina is treated with an acid at a pH of 2-6.5 under an equilibrium condition and the treated alumina is dried and/or fired to obtain the desired alumina carrier which is porous alumina which has a specific surface area of 10m<2>/g or above and a particle size of 0.03-100mu, whose 2.4wt% aq. dispersion has a pH of 3.0-6.5 and at least part of which is converted into hydrated alumina when treated with water at 70-250 deg.C. Alternatively, the alumina carrier can be prepd. in such a manner (i) that hydrated alumina or porous intermediate alumina is mixed with an ammonium salt powder or is brought into contact with an ammonium salt soln. and the mixture is fired, or (ii) that hydrated alumina or porous intermediate alumina is fired in a hydrogen chloride atmosphere.
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