Pilkington Plc

Pilkington Group Limited

David William Holden

John Richard Holland

Karikath Sukumar Varma

Stephen Ian Bond

Karikath Su Varma

Angela Yuk Fungt Cheung

Anna L Staunton

Jeffrey Williams

Heinz Wilhelm Holscher

Allan Stuart Dale

Fire resistant glazings comprise a fire resistant interlayer based upon a silicate waterglass are characterized by the incorporation of aluminum ions. The aluminate is incorporated as a solution which has been partially neutralized using hydroxycarboxylic acid which is preferably citric acid. The incorporation of aluminum provides glazings have improved fire resistance and impact properties.

Fire resistant glazing

Fire resistant glazings having improved properties comprising a silicate based interlayer which contains from 35% to 43% by weight of water may be produced using a cast in place process. The amount of water in the interlayer is reduced by concentrating the silicate solution or by introducing silica in the form of a silica sol. Preferably a mixture of an aqueous sol and an organosol is used. Polyhydroxy compounds and saccharides may be incorporated into the interlayer to improve the properties thereof and to reduce the water content. The silicate based formulations are pourable and can be used in a cast in place production process and subsequently cured to form an optically clear interlayer.

Method for the production of fire resistant glazings

An aqueous mixture for the production of fire resistant glazings comprising: at least one alkali metal silicate, at least one glass, glass-ceramic and/or ceramic additive, and water, wherein the at least one glass, glass-ceramic and/or ceramic additive has at least one boron containing moiety directly or indirectly attached to a surface thereof by covalent or ionic bonding.

Fire resistant glazings

A transparent fire resistant glazing comprising an intumescent interlayer, wherein the intumescent interlayer comprises an alkali metal silicate and a foam improvement additive, wherein the foam improvement additive comprises a polymer and/or oligomer and/or salts thereof, wherein said polymer, oligomer and/or salts thereof each contain at least one organic moiety having at least one hydrogen-bondable functional group covalently attached thereto.

The incorporation of polyvalent metal ions into a silicate based interlayer in a laminated fire resistant glazing produced using a cast in place process provides an improvement in the properties of those glazings. The preferred metal ions are aluminium ions and zirconium ions. The preferred polyvalent metal compounds are those which are disclosed in EP 1206349 and WO 2004/014813.

Solutions comprising a sodium silicate waterglass having a modulus of less than 3 and at least 8% by weight of an organic polyhydroxy compound such as glycerol are useful in the production of interlayers used in fire resistant glass laminates. The solutions are dried on a flat surface such as glass to produce a clear intumescent interlayer having improved impact resistance. The dried interlayer may be removed from the surface in the form of an elastomeric material which may also be used as an interlayer in a fire resistant glazing.

Process for the production of an intumescent fire resistant layer by drying a waterglass solution on the surface of a glass substrate are carried out in the presence of a salt of a carbonic acid or an &#x3b1;-hydroxy carboxylic acid such as potassium citrate. The drying is preferably carried out at a rate which reduces of pH of the solution by no more than 2 units during an initial drying period of 5 hours. The resulting interlayers provide improved fire resistance.

Production of fire resistant laminates

Novel waterglass compositions comprise a zirconium containing anionic aggregate, preferably potassium zirconium carbonate or ammonium zirconium carbonate, in a quantity sufficient to provide at least 0.5% as zirconium metal. The compositions can be dried and/or gelled to form optically clear interlayers useful in the production of fire resistant glass laminates. The incorporation of the zirconium containing aggregate improves the fire resistant performance of the laminates.

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Wigan, United Kingdom

David William Holden