Fire resistant calcium sulphate-based products

Patent metadata

Field	Value
Publication number	US-10584063-B2
Application number	US-201515525523-A
Country	US
Kind code	B2
Filing date	Nov 17, 2015
Priority date	Nov 21, 2014
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

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 calcium sulphate-based wallboard comprising:
at least 40 wt % gypsum (based on a total weight of the wallboard), 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), and
the metal salt is a metal nitrate or a chloride of magnesium, copper, zinc or aluminum.

2. The calcium sulphate-based wallboard according to claim 1 , wherein the pozzolan source is a kaolinitic clay additive and 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 calcium sulphate-based wallboard according to claim 1 , wherein the pozzolan source is rice husk ash or diatomaceous earth and is included in an amount equal to or greater than 20 wt %.

4. The calcium sulphate-based wallboard according to claim 1 , wherein the wt % amount of metal salt and the wt % amount of pozzolan source is equal.

5. The calcium sulphate-based wallboard according to claim 1 , comprising 50-85 wt % gypsum.

6. The calcium sulphate-based wallboard according to claim 1 , wherein the metal salt is magnesium nitrate or magnesium chloride.

7. A calcium sulphate-based wallboard formed by a process comprising:
drying an aqueous slurry between at least two liners, the aqueous slurry including at least 40 wt % calcined gypsum (based on a total weight of the wallboard), a pozzolan source, and a metal salt additive, wherein
the metal salt additive is provided in the slurry in an amount between 5 and 25 wt % (based on the weight of the calcined gypsum, pozzolan source and metal salt), and
the metal salt is a metal nitrate or a chloride of magnesium, copper, zinc or aluminum.

8. The calcium sulphate-based wallboard according to claim 7 , wherein the pozzolan source is a kaolinitic clay additive and is included in the slurry in an amount between 5 and 30 wt % (based on the weight of the calcined gypsum, clay additive and metal salt additive).

9. The calcium sulphate-based wallboard according to claim 7 , wherein the pozzolan source is rice husk ash or diatomaceous earth and is included in the slurry in an amount equal to or greater than 25 wt %.

10. The calcium sulphate-based wallboard according to claim 7 , wherein a clay additive is provided in a wt % amount that is equal to the wt % amount of metal salt.

11. The calcium sulphate-based wallboard according to claim 7 , wherein the calcined gypsum is included in the slurry in an amount of 50-85 wt %.

12. A calcium sulphate-based composition for use in forming a calcium sulphate-based wallboard by drying an aqueous slurry of the composition, the calcium sulphate-based composition comprising:
at least 40 wt % calcined gypsum (based on a total weight of the composition), 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 calcined gypsum, pozzolan source and metal salt), and
the metal salt is a metal nitrate or a chloride of magnesium, copper, zinc or aluminum.

13. The calcium sulphate-based composition according to claim 12 , wherein the pozzolan source is a kaolinitic clay additive and is included in the composition in an amount between 5 and 30 wt % (based on the weight of the calcined gypsum, clay additive and metal salt additive).

14. The calcium sulphate-based composition according to claim 12 , wherein the pozzolan source is rice husk ash or diatomaceous earth and is included in an amount equal to or greater than 25 wt %.

15. The calcium sulphate-based composition according to claim 12 , wherein a clay additive is provided in a wt % amount that is equal to the wt % amount of metal salt.

16. The calcium sulphate-based composition according to claim 12 , wherein the calcined gypsum is included in an amount of 50-85 wt %.

17. The calcium sulphate-based composition according to claim 12 , wherein the metal salt is magnesium nitrate or magnesium chloride.

18. A method of forming a calcium sulphate-based wallboard, the method comprising:
drying an aqueous slurry between at least two liners, the aqueous slurry including at least 40 wt % calcined gypsum (based on a total weight of the composition), 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 calcined gypsum, pozzolan source and metal salt), and
the metal salt is a metal nitrate or a chloride of magnesium, copper, zinc or aluminum.

19. A calcium sulphate-based wallboard comprising:
gypsum, a pozzolan source, and a metal 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),
the metal salt is a nitrate or a chloride, and
the pozzolan source is kaolinitic clay.

20. The calcium sulphate-based wallboard according to claim 19 , wherein the kaolinitic clay is included in an amount between 5 and 30 wt % (based on the weight of the gypsum, kaolinitic clay and metal salt additive).

21. The calcium sulphate-based wallboard according to claim 19 , wherein the wt % amount of metal salt and the wt % amount of kaolinitic clay is equal.

22. The calcium sulphate-based wallboard according to claim 19 , further comprising 50-85 wt % gypsum.

23. The calcium sulphate-based wallboard according to claim 19 , wherein the metal salt is a metal nitrate or a chloride of magnesium, copper, zinc or aluminium.

24. The calcium sulphate-based wallboard according to claim 23 , wherein the metal salt is magnesium nitrate or magnesium chloride.

Assignees

• Saint Gobain Placo

Inventors

• Brooks Laura
• Fisher Robin
• Rideout Jan

Classifications

• C04B2111/34

  Non-shrinking or non-cracking materials · CPC title

• C04B2111/28

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

• C04B28/14 Primary

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

• C04B22/124

  Chlorides of ammonium or of the alkali or alkaline earth metals, e.g. calcium chloride · CPC title

• C04B22/08

  Acids or salts thereof {(C04B22/0013 takes precedence)} · CPC title