Calcium sulphase-based products
AssigneeSaint-Gobain Placo
InventorsLaura BROOKS, Robin FISHER, Jan RIDEOUT
Life of this patent
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Abstract
A calcium sulphate-based product including gypsum and a shrinkage resistance additive. The shrinkage resistance additive is a metal nitrate, hydroxide, acetate or sulphate and is preferably provided in an amount greater than 4 wt % (based on the amount of additive and gypsum). The additive may be a nitrate of an alkali metal (e.g. potassium), an alkaline earth metal (e.g. magnesium or calcium), a transition metal (e.g. iron or zinc) or aluminium.
Claims28
A calcium sulphate-based product comprising gypsum and a shrinkage resistance additive provided in an amount between 4 and 40 wt % based on the weight of gypsum and additive wherein the shrinkage resistance additive is a metal nitrate, hydroxide, acetate or sulphate.
2-7. (canceled)
A calcium sulphate-based product comprising gypsum and a shrinkage resistance additive wherein the product is produced by drying an aqueous slurry comprising calcined gypsum and between 4.5 and 50 wt % shrinkage resistance additive (based on the weight of gypsum and additive), the shrinkage resistance additive being a metal nitrate, hydroxide, acetate or sulphate.
9-14. (canceled)
A calcium sulphate-based composition for use in forming a calcium sulphate-based product by drying an aqueous slurry of the calcium sulphate-based composition, the calcium sulphate-based composition comprising calcined gypsum and between 4.5 and 50 wt % of a shrinkage resistance additive (based on the amount of gypsum and additive), wherein the shrinkage resistance additive is a metal nitrate, hydroxide, acetate or sulphate.
21-26. (canceled)
33-48. (canceled)
A calcium sulphate-based product comprising gypsum and a shrinkage resistance additive provided in an amount less than 40 wt % based on the weight of gypsum and additive wherein the shrinkage resistance additive is a nitrate of an alkali metal, an alkaline earth metal, a transition metal or aluminium, the hydroxide or acetate of magnesium, aluminium, zinc or iron, or the sulphate of magnesium, aluminium or zinc.
A calcium sulphate-based product comprising gypsum and a shrinkage resistance additive wherein the product is produced by drying an aqueous slurry comprising calcined gypsum less than 50 wt % shrinkage resistance additive (based on the weight of gypsum and additive), the shrinkage resistance additive being a nitrate of an alkali metal, an alkaline earth metal, a transition metal or aluminium, the hydroxide or acetate of magnesium, aluminium, zinc or iron, or the sulphate of magnesium, aluminium or zinc.
A calcium sulphate-based composition for use in forming a calcium sulphate-based product by drying an aqueous slurry of the calcium sulphate-based composition, the calcium sulphate-based composition comprising calcined gypsum and less than 50 wt % of a shrinkage resistance additive (based on the amount of gypsum and additive), wherein the shrinkage resistance additive is a nitrate of an alkali metal, an alkaline earth metal, a transition metal or aluminium, the hydroxide or acetate of magnesium, aluminium, zinc or iron, or the sulphate of magnesium, aluminium or zinc.
Dependencies are inferred from the claim text.