Fire resistant calcium sulphate-based products

Patent metadata

Field	Value
Publication number	US-11198645-B2
Application number	US-202016822664-A
Country	US
Kind code	B2
Filing date	Mar 18, 2020
Priority date	Nov 21, 2014
Publication date	Dec 14, 2021
Grant date	Dec 14, 2021

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.

First claim

The invention claimed is:

1. A gypsum wallboard comprising:
gypsum, a pozzolan source and a metal salt additive, wherein:
the gypsum is provided in an amount of 40% or greater based on a total weight of the wallboard;
the metal salt additive is a magnesium salt that decomposes between a temperature of 300-500° C. to yield a metal oxide; and
the pozzolan source is selected from fly ash, rice husk ash, volcanic ash or pumice, micro-silica, silica fume, or clay material.

2. The gypsum wallboard 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 additive).

3. The gypsum wallboard according to claim 2 , wherein the pozzolan source is included in an amount between 4 and 9 wt% (based on the weight of the gypsum, pozzolan source and metal salt additive).

4. The gypsum wallboard 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 additive).

5. The gypsum wallboard according to claim 4 , wherein the metal salt additive is included in an amount between 2 and 9 wt% (based on the weight of the gypsum, pozzolan source and metal salt additive).

6. The gypsum wallboard according to claim 1 , 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 additive).

7. The gypsum wallboard according to claim 6 , wherein the gypsum is provided in an amount between 65 and 85 wt% (based on the weight of the gypsum, pozzolan source and metal salt additive).

8. The gypsum wallboard according to claim 1 , wherein a wt% of pozzolan source and wt% metal salt additive are equal.

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

10. The gypsum wallboard according to claim 2 , 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 additive).

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

• C04B22/10

  containing carbon in the anion, e.g. carbonates · CPC title

• Y02W30/91

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

• C04B14/10

  Clay {(sepiolite C04B14/042; grog C04B18/025)} · CPC title