Abstract: 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.

Abstract: 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.

Abstract: A laminated structure comprising at least one glazing pane, at least one interlayer, and a seal covering at least one edge of the interlayer, wherein the seal comprises a nano-particulate silicon oxide.

Abstract: The addition of nanoparticulate silica to sealants which are applied to the exposed edges of fire resistant laminated glazings provides an improved seal. Preferably the silica is present as an Ormosil dispersed in a polymerisable organic medium. Methods for applying such a medium to the edges of a glazing and polymerising it in situ are also claimed. The seals can be used to replace known metal tapes. The use of transparent seals provides a seal having an improved appearance.