| 摘要 |
PROBLEM TO BE SOLVED: To provide a cement additive which has good storage stability and shows a reactivity similar to that of an immaculate organic acid without encapsulation after kneading.SOLUTION: (1) A cement additive is prepared by encapsulating an organic acid, or the core material, with a capsule wall material, and the content of the core material is 90-99.5 pts. mass to the total content of the core material and the capsule wall material of 100 pts. mass. (2) In the cement additive specified by (1), the capsule wall material is one or more selected from waxes, hardened oils, paraffin and soft resins. (3) In the cement additive specified by (1) and (2), the organic acid is one or more selected from citric, tartaric, gluconic and malic acids and their alkali salts. |
