FIRE-RESISTANT CALCIUM SULPHATE-BASED PRODUCTS

• US 20170334783A1
• Filed: 11/17/2015
• Published: 11/23/2017
• Est. Priority Date: 11/21/2014
• Status: Active Grant

• Current Assignee: Saint-Gobain Placo
• Original Assignee: Saint-Gobain Placo
• Inventors: BROOKS, Laura, FISHER, Robin, RIDEOUT, Jan
• Granted Patent: US 10,662,113 B2
• Time in Patent Office: Days
• CPC Class Codes: C04B 14/062 Microsilica, e.g. colloïdal silica preparing microsilica slurries or suspensions C04B18/148
• CPC Class Codes: C04B 14/08 Diatomaceous earth
• CPC Class Codes: C04B 14/106 Kaolin
• CPC Class Codes: C04B 14/14 Minerals of vulcanic origin granite C04B14/048
• CPC Class Codes: C04B 14/16 porous, e.g. pumice
• CPC Class Codes: C04B 18/08 Flue dust , i.e. fly ash
• CPC Class Codes: C04B 18/101 Burned rice husks or other burned vegetable material
• CPC Class Codes: C04B 18/146 Silica fume
• CPC Class Codes: C04B 2111/28 Fire resistance, i.e. materials resistant to accidental fires or high temperatures
• CPC Class Codes: C04B 2111/34 Non-shrinking or non-cracking materials
• CPC Class Codes: C04B 22/08 Acids or salts thereof C04B22/0013 takes precedence
• CPC Class Codes: C04B 22/085 containing nitrogen in the anion, e.g. nitrites
• CPC Class Codes: C04B 24/42 Organo-silicon compounds
• CPC Class Codes: C04B 28/14 containing calcium sulfate cements gypsum-paper plates E04C
• CPC Class Codes: Y02W 30/91 Use of waste materials as fillers for mortars or concrete

Abstract

The present invention provides calcium sulphate-based product having reduced shrinkage after exposure to high temperatures, the product comprising gypsum, a pozzolan source (e.g. in an amount between 4-27 wt %) and a metal salt additive (in an amount between 0.5 and 10 wt %). The pozzolan source may be selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil. The metal salt additive may be a metal salt which decomposes between a temperature of 300-500° C. to yield a metal oxide, e.g. magnesium nitrate.

Claims

1. A calcium sulphate-based product comprising gypsum, a pozzolan source and a metal salt additive wherein the gypsum is provided in an amount between 65 and 98 wt % (based on the weight of the gypsum, pozzolan source and metal salt) and wherein the metal salt is selected from calcium nitrate and salts of magnesium, copper, zinc, iron or aluminum.

2. A calcium sulphate-based product according to claim 1 wherein the pozzolan source is included in an amount between 4 and 27 wt % (based on the weight of the gypsum, pozzolan source and metal salt).

4. A calcium sulphate-based product according to claim 1 wherein the metal salt additive is included in an amount between 0.5 and 10 wt % (based on the weight of the gypsum, pozzolan source and metal salt).

15. A calcium sulphate-based product according to claim 1 wherein the wt % of pozzolan source and wt % metal salt are equal.

20. A calcium sulphate-based product according to claim 1 wherein the pozzolan source is selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil.

21. A calcium sulphate-based product according to claim 1 where the metal salt additive is a metal salt which decomposes between a temperature of 300-500°

C. to yield a metal oxide.

23. A calcium sulphate-based product according to claim 1 wherein the metal salt is a nitrate, a carbonate, a hydrogen carbonate, a sulphate, a hydroxide or chloride.

24. A calcium sulphate-based product according to claim 1 wherein the metal salt is magnesium nitrate.

3. (canceled)

5. (canceled)

6. (canceled)

7. (canceled)

8. (canceled)

9. (canceled)

10. A calcium sulphate-based product formed from drying an aqueous slurry containing calcined gypsum, a pozzolan source and a metal salt additive wherein the calcined gypsum is provided in the slurry in an amount between 60 and 95 wt % (based on the weight of the calcined gypsum, pozzolan source and metal salt) and wherein the metal salt is selected from calcium nitrate and salts of magnesium, copper, zinc, iron or aluminum.

11. A calcium sulphate-based product according to claim 10 wherein the pozzolan source is included in the slurry in an amount between 5 and 30 wt %.

13. A calcium sulphate-based product according to claim 10 wherein the metal salt additive is included in the slurry in an amount between 1 and 15 wt %.

12. (canceled)

14. (canceled)

16. (canceled)

17. (canceled)

18. (canceled)

19. (canceled)

22. (canceled)

25. 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, a pozzolan source and a metal salt, wherein the calcined gypsum is provided in the composition in an amount between 60 and 95 wt % (based on the weight of the calcined gypsum, pozzolan source and metal salt) and wherein the metal salt is selected from calcium nitrate and salts of magnesium, copper, zinc, iron or aluminum.

26. A calcium sulphate-based composition according to claim 25 wherein the pozzolan source is included in an amount between 5 and 30 wt %.

28. A calcium sulphate-based composition according to claim 25 wherein the metal salt additive is included in an amount between 1 and 15 wt %.

30. A calcium sulphate-based composition according to claim 25 wherein the wt % of pozzolan source and wt % metal salt are equal.

35. A calcium sulphate-based composition according to claim 25 wherein the pozzolan source is selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil.

36. A calcium sulphate-based composition according to claim 25 wherein the metal salt additive is a metal salt which decomposes between a temperature of 300-500°

C. to yield a metal oxide.

38. A calcium sulphate-based composition according to claim 36 wherein the metal salt is a nitrate, a carbonate, a hydrogen carbonate, a sulphate, a hydroxide or chloride.

39. A calcium sulphate-based composition according to claim 36 wherein the metal salt is magnesium nitrate.

27. (canceled)

29. (canceled)

31. (canceled)

32. (canceled)

33. (canceled)

34. (canceled)

37. (canceled)

40. A method of forming a calcium sulphate-based product by drying an aqueous slurry comprising a composition according to 25.

41-58. -58. (canceled)