| 摘要 |
PROBLEM TO BE SOLVED: To mass produce a powdery dispersant at a high recovery ratio without lowering its dispersion performance. SOLUTION: In the method for producing the powdery cement dispersant, an aqueous solution containing the following A component in 5 to 70 mass% is introduced into a spray drier in which a spray apparatus part is provided with a nozzle, and is sprayed and dried at a hot air inlet temperature of 150 to 250°C and a hot air outlet temperature of 80 to 150°C: the A component is a water soluble vinyl copolymer containing the following A1 component in 40 to 85 mol%, the A2 component in 15 to 60 mol%, and the A3 component in 0 to 5 mol% (100 mol% in total), and having a number average molecular weight of 2,000 to 5,000: the A1 component is one or more selected from olefin monocarboxylic acid and a salt thereof; the A2 component is one or more selected from alkoxypolyethylene glycol(meth)acrylate and (meth)allylsulfonate; and the A3 component is one or more selected from alkyl (meth)acrylate and hydroxyalkyl(meth)acrylate. COPYRIGHT: (C)2004,JPO |
