Fireproof glazing

摘要

The fire proof transparent glazing comprises glass sheets (7, 8), an intumescent material layer present between the glass sheets, and a thermoplastic sheet associated with the glass sheets. The intumescent layer is a hydrated alkaline poly-silicate layer, and is prepared by systematically producing silica from an industrial silicate solution, adjusting the water content of the solution at a value of less than 40% to obtain surplus from a colloidal silica suspension and degassing and/or vacuum dehydrating the resultant solution. The fire proof transparent glazing comprises glass sheets (7, 8), an intumescent material layer present between the glass sheets, and a thermoplastic sheet associated with the glass sheets. The intumescent layer is a hydrated alkaline poly-silicate layer, and is prepared by systematically producing silica from an industrial silicate solution, adjusting the water content of the solution at a value of less than 40% to obtain surplus from a colloidal silica suspension and degassing and/or vacuum dehydrating the resultant solution. The preparation of the silicate solution comprises increasing the proportion of dry material by adding alkaline hydroxide in the form of concentrated solution and/or pellets to the silicate solution, and optionally drying the obtained material. The silicate solution enriched in dry material has a molar ratio of silicon oxide/metal oxide of 1.4-2. The colloidal silica comprises particles having a dimension of 60-130 nm. The molar ratio of silica and alkali is 3.5-6. The intumescent layer has a thickness of 2-8 mm. The adhesion of the intumescent layer with glass sheets is enhanced by applying an adhesion promoter on the sheets or by incorporating the promoter in the intumescent composition. An independent claim is included for a process for the preparation of fire proof transparent glazing.