| 摘要 |
PROBLEM TO BE SOLVED: To obtain a foaming agent having excellent foam persistence and sufficient foamability by including a betaine-type amphoteric surfactant, a higher alcohol and an alkylene oxide adduct thereof. SOLUTION: This foaming agent comprises (A) a betaine-type amphoteric surfactant of formula I [R1 and R2 are each methyl or ethyl; X is R or RCONH-(CH2 )n ; R is an aliphatic hydrocarbon group; (n) is 1-12], e.g. dimethyllaurylaminoacetic acid betaine, (B) a higher alcohol, e.g. octyl alcohol, and an alkylene oxide adduct thereof of formula II [R3 is an 8-20C hydrocarbon group; M is H or methyl; (m) is 0-5]. The alkylene oxide is exemplified by ethylene oxide and the number of added mol is 0-5. The mixing ratio of the components A/B is set to (99/1) (30-70) expressed in terms of fineness weight ratio. The addition amount of the foaming agent for the concrete is ordinary 0.01-5 wt.% based on water in terms of the fineness. |
