Fire resistant calcium sulphate-based products

Patent metadata

Field	Value
Publication number	US-11117835-B2
Application number	US-202016750623-A
Country	US
Kind code	B2
Filing date	Jan 23, 2020
Priority date	Nov 21, 2014
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

The present invention provides a calcium sulphate-based product (e.g. a wall board) comprising gypsum, a pozzolan source such as a clay additive, rice husk ash or diatomaceous earth and a metal salt additive. The product may be produced by drying an aqueous slurry comprising calcined gypsum, the pozzolan source and the metal salt additive. The clay additive may be a kaolinitic clay. The metal salt additive may be a magnesium salt e.g. magnesium nitrate, magnesium chloride or magnesium hydroxide.

First claim

The invention claimed is:

1. A gypsum wallboard comprising:
40 wt% or greater gypsum,
a pozzolan source, and
a metal salt additive, wherein:
the metal salt additive is provided in an amount between 5 and 25 wt% based on the weight of the gypsum, pozzolan source and metal salt additive, and
the metal salt additive is a salt of magnesium, copper, zinc or aluminium.

2. The wallboard according to claim 1 , wherein
the pozzolan source is a kaolinitic clay additive, and
The pozzolan source is included in an amount between 5 and 30 wt% based on the weight of the gypsum, clay additive and metal salt additive.

3. The wallboard according to claim 2 , wherein the clay additive is included in an amount between 10 and 25 wt%.

4. The wallboard according to claim 1 , wherein
the pozzolan source is rice husk ash or diatomaceous earth, and
the pozzolan source is included in an amount equal to or greater than 20 wt%.

5. The wallboard according to claim 1 , wherein the metal salt is a nitrate, carbonate, hydrogen carbonate, sulphate, hydroxide or chloride.

6. The wallboard according claim 1 , wherein the wt% amount of metal salt and the wt% amount of pozzolan source is equal.

7. The wallboard according to claim 1 , wherein the gypsum is provided in an amount of 50-85 wt%.

8. A gypsum wallboard comprising:
40 wt% or greater of gypsum,
a pozzolan source, and
a metal salt additive, wherein:
the metal salt additive is provided in an amount of 5-25 wt% based on the amount of gypsum, pozzolan and metal salt additive, and
the metal salt additive is a metal hydroxide, a metal hydrogen carbonate, or a chloride of magnesium, copper, zinc or aluminium.

9. The wallboard according to claim 8 , wherein
the pozzolan source is a kaolinitic clay additive, and
the pozzolan source is included in an amount between 5 and 30 wt% based on the weight of the gypsum, clay additive and metal salt additive.

10. The wallboard according to claim 9 , wherein the clay additive is included in an amount between 10 and 25 wt%.

11. The wallboard according to claim 8 , wherein
the pozzolan source is rice husk ash or diatomaceous earth, and
the pozzolan source is included in an amount equal to or greater than 20 wt%.

12. The wallboard according claim 8 , wherein the wt% amount of metal salt and the wt% amount of pozzolan source is equal.

13. The wallboard according to claim 8 , wherein the gypsum is provided in an amount of 50-85 wt%.

Assignees

• Saint Gobain Placo

Inventors

• Brooks Laura
• Fisher Robin
• Rideout Jan

Classifications

• Y02W30/91

  Use of waste materials as fillers for mortars or concrete · CPC title

• C04B2111/28

  Fire resistance, i.e. materials resistant to accidental fires or high temperatures · CPC title

• C04B14/106

  Kaolin · CPC title

• C04B14/08

  Diatomaceous earth · CPC title

• C04B28/14 Primary

  containing calcium sulfate cements {(gypsum-paper plates E04C)} · CPC title