| abstract |
A defoamer composition is obtained when a mixture of certain siloxane-containing components, a finely divided filler, a reaction catalyst and at least one compound having in each molecule at least 1 group expressed by -COR5, -COOR6 or -(OR7)n- is heated. R5 and R6 are the hydrogen atom or saturated or unsaturated monovalent hydrocarbon groups, R7 is a divalent hydrocarbon group having two to six carbon atoms, and the average value of n is at least 1. The siloxane-containing components comprise resinous polyorganosiloxanes and typically, polydiorganosiloxanes. The heated mixture is useful for defoaming anionic systems. |