Gypsum board and gypsum slurry formed using a phosphorus containing compound
In general, the present invention is directed to the use of particular phosphorus containing compounds for making a gypsum board. The phosphorus containing compound may be a phosphite or a phosphate having a certain formula. In this regard, the present invention is directed to a slurry for making a gypsum board wherein the slurry includes such phosphorus containing compound. The present invention is also directed to a method of making a gypsum board from the slurry as well as a resulting gypsum board.
1. A gypsum board comprising
a gypsum core comprising
gypsum, and
a phosphorus containing compound comprising a phosphite, a phosphate having the formula P(O) n (X) m wherein n is from 0 to 4, m is from 1 to 6, the sum of n and m is from 3 to 6, and X is halogen, sulfur, or selenium, a salt thereof, or a mixture thereof.
2. The gypsum board of claim 1 , wherein the phosphorus containing compound comprises a salt.
3. The gypsum board of claim 2 , wherein the salt includes a monohalophosphate.
4. The gypsum board of claim 2 , wherein the salt includes an alkali metal, an alkaline earth metal, a transition metal, or a combination thereof.
5. The gypsum board of claim 1 , wherein the phosphorus containing compound comprises from 0.001 lbs/MSF to 150 lbs/MSF of the board weight.
6. The gypsum board of claim 1 , wherein the board exhibits a nail pull resistance of 70 lb f or more when measured according to ASTM C1396, a compressive strength of 300 psi or more when measured according to ASTM C1396, or both.
7. The gypsum board of claim 1 , wherein the phosphorus containing compound comprises a phosphite.
8. The gypsum board of claim 1 , wherein the phosphorus containing compound comprises a phosphate having the formula P(O) n (X) m wherein n is from 0 to 4, m is from 1 to 6, the sum of n and m is from 3 to 6, and X is halogen, sulfur, or selenium, a salt thereof.
9. The gypsum board of claim 8 , wherein X includes fluoro.
10. The gypsum board of claim 8 , wherein n is from 2 to 3.
11. The gypsum board of claim 8 , wherein m is from 1 to 2.
12. The gypsum board of claim 1 , wherein the phosphorus containing compound comprises a phosphate having the formula P(0) n (X) m wherein n is from 1 to 4, m is from 1 to 6, the sum of n and m is from 3 to 6, and X is halogen, sulfur, or selenium, a salt thereof.
13. The gypsum board of claim 1 , wherein the phosphorus containing compound comprises a halophosphate.
14. The gypsum board of claim 1 , wherein the phosphorus containing compound comprises sodium monofluorophosphate.
15. The gypsum board of claim 1 , wherein the phosphorus containing compound comprises from 0.001 lbs/MSF to 10 lbs/MSF of the board weight.
16. The gypsum board of claim 1 , wherein the gypsum core further comprises a dispersant.
17. The gypsum board of claim 16 , wherein the dispersant comprises a sulfonate, a polycarboxylate ether, a polycarboxylate ester, or a mixture thereof.
18. The gypsum board of claim 1 , wherein the board exhibits a nail pull resistance of 70 lb f or more when measured according to ASTM C1396.
19. The gypsum board of claim 1 , wherein the board exhibits a compressive strength of 300 psi or more when measured according to ASTM C1396.
20. A method for making the gypsum board of claim 1 , the method comprising
providing a first facing material,
depositing a gypsum slurry comprising stucco, water, and the phosphorus containing compound on the first facing material,
providing a second facing material on the gypsum slurry, and
allowing the stucco to convert to calcium sulfate dihydrate.
21. A gypsum board comprising
a gypsum core comprising
gypsum, and
a phosphorus containing compound comprising a sodium monofluorophosphate.