| 摘要 |
An additive for alkali metal silicate solutions, comprising a quaternary ammonium compound having the general formula (1) R1R2R3R4N+OH−, wherein R1, R2, R3 and R4 which may be the same or different represent alkyl groups, hydroxy-substituted alkyl groups, alkaryl groups, hydroxy-substituted alkaryl groups comprising from 1 to 12 carbon atoms, or groups having the general formula —[CH2]n-N+R5R6R7 wherein n is an integer having a value of from 1 to 12, the group —[CH2]n may be hydroxy-substituted, and R5, R6 and R7 which may be the same or different represent alkyl groups, hydroxy-substituted alkyl groups, alkaryl groups or hydroxy-substituted alkaryl groups comprising from 1 to 12 carbon atoms; with the proviso that at least one of the groups R1, R2, R3, R4, R5, R6 and R7 represents a hydroxy-substituted alkyl group or a hydroxy-substituted alkaryl group comprising at least 2 carbon atoms wherein the hydroxy substituent is not located on a carbon atom which is bonded to a nitrogen atom. |
