| 摘要 |
PURPOSE:To provide the titled dispersant having an excellent viscosity decreasing effect, storage stability and economical efficiency, which comprises, as an active ingredient, a product obtd. from a particular modified ligninsulfonate, naphthalene(di)sulfonic acid, and formaldehyde. CONSTITUTION:Sulfite cellulose pulp waste liquid (a) is mixed with NaOH (b) in an amt. of 5-20% based on the solid content of the component a. The mixture is kept at 150-200 deg.C for 1-2hr while air or oxygen is blown into the mixture, thereby causing an oxidation reaction and obtaining a modified ligninsulfonate (D). Sulfuric acid and water are added to a mixture of 100pts.wt. (hereinafter referred to as 'pts.') naphthalenesulfonic acid (A) with 5-20pts. naphthalenedisulfonic acid (B) composed mainly of 6-naphthalenedisulfonic acid to allow the mixture to acidity. The acidified mixture is heated at 80-95 deg.C and mixed with 20-25pts. about 37% formaldehyde (C) and then with 20-100pts. component C and 5-50pts. component D. The mixture is allowed to react at 90-120 deg.C for 5-20hr. The reaction product is used as an active ingredient and neutralized to obtain the titled dispersant.
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