Patent ID: 8105500

Claim:
A process for producing a slurry, which comprises: adding a slurry rheology modifier to a slurry composition, wherein the slurry rheology modifier comprises a first water-soluble low-molecular compound (referred to hereinafter as compound (A)) and a second water-soluble low-molecular compound (referred to hereinafter as compound (B)) being different from the compound (A), wherein the viscosity of an aqueous solution at 20° C. prepared by mixing an aqueous solution S A (with a viscosity at 20° C. of 100 mPa's or less) of compound (A) with an aqueous solution S n (with a viscosity at 20° C. of 100 mPa's or less) of compound (B) in the ratio of 50/50 by weight can be at least twice as high as the viscosity of either aqueous solution before mixed; wherein said adding step comprises preparing a slurry containing one compound (A) or (B) for the slurry rheology modifier, powder and water, and then adding the other compound (A) or (B) to the slurry; wherein compound (A) and compound (B) having the following Necessary Conditions 1 and 3: Necessary Condition 1: a combination of compound (A) and compound (B) is selected from (1) combination of a compound selected from amphoteric surfactants and a compound selected from anionic surfactants, (2) combination of a compound selected from cationic surfactants and a compound selected from anionic aromatic compounds and (3) combination of a compound selected from cationic surfactants and a compound selected from NaBr, KBr and HBr, Necessary Condition 3: the amphoteric surfactant is at least one selected from dodecanoic acid amide propyl betaine, octadecanoic acid amide propyl betaine and dodecyl dimethyl aminoacetic acid betaine, the anionic surfactant is at least one selected from POE (3) dodecyl ether sulfate, POE (2) dodecyl ether sulfate and POE (4) dodecyl ether sulfate, the cationic surfactant is at least one selected from alkyl (C 10-26 ) trimethyl ammonium salt, alkyl (C 10-26 ) pyridinium salt, alkyl (C 10-26 ) imidazolinium salt and alkyl (C 10-26 ) dimethyl benzyl ammonium salt, the anionic aromatic compound is at least one selected from salicylic acid, p-toluenesulfonic acid, sulfosalicylic acid, benzoic acid, m-sulfobenzoic acid, p-sulfobenzoic acid, 4-sulfophthalic acid, 5-sulfoisophthalic acid, p-phenol sulfonic acid, m-xylene-4-sulfonic acid, cumene sulfonic acid, methyl salicylic acid, styrene sulfonic acid, chlorobenzoic acid and a salt of the before mentioned acid; wherein the powder is selected from the group consisting of cement, gypsum, and filler; and wherein the filler is selected from the group consisting of calcium carbonate, fly ash, blast furnace slag, and fumed silica.