Gypsum composition comprising uncooked starch having mid-range viscosity, and methods and products related thereto

Patent metadata

Field	Value
Publication number	US-10919808-B2
Application number	US-201815934088-A
Country	US
Kind code	B2
Filing date	Mar 23, 2018
Priority date	Jul 18, 2017
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

Disclosed are product (e.g., panels), slurry, and methods relating to an uncooked starch having a mid-range peak viscosity (i.e., from about 120 Brabender Units to about 900 Brabender Units).

First claim

The invention claimed is:

1. A gypsum board comprising:
a set gypsum core disposed between two cover sheets, the core formed from a slurry comprising stucco, water, and at least one uncooked non-substituted starch having a peak viscosity of from about 120 Brabender Units to about 900 Brabender Units when the viscosity is measured by putting the starch in a slurry with water at a starch concentration of 15% solids, and using a VISCOGRAPH®-E instrument set at 75 rpm and 700 cmg, where the starch is heated from 25° C. to 95° C. at a rate of 3° C./minute, the slurry is held at 95° C. for ten minutes, and the starch is cooled to 50° C. at a rate of −3° C./minute.

2. The gypsum board of claim 1 , wherein the uncooked non-substituted starch has a bulk density of from about 40 pcf to about 45 pcf.

3. The gypsum board of claim 1 , wherein the uncooked non-substituted starch has a peak viscosity of from about 300 BU to about 875 BU.

4. The gypsum board of claim 1 , wherein the uncooked non-substituted starch is acid-modified.

5. The gypsum board of claim 1 , wherein the uncooked non-substituted starch has a cold water viscosity of less than about 50 centipoise, as measured according to the BROOKFIELD® viscometer method.

6. The gypsum board of claim 1 , wherein the slurry further comprises a dispersant.

7. The gypsum board of claim 1 , wherein the slurry further comprises a polyphosphate.

8. The gypsum board of claim 7 , wherein the polyphosphate is sodium trimetaphosphate, and the slurry further comprises a dispersant.

9. The gypsum board of claim 1 , wherein the uncooked non-substituted starch has a bulk density of from about 35 pcf to about 45 pcf, the uncooked non-substituted starch is acid-modified, the uncooked non-substituted starch has a cold water viscosity of less than about 50 centipoise, as measured according to the BROOKFIELD® viscometer method, and the board has a density of from about 16 pcf to about 35 pcf.

10. The gypsum board of claim 9 , wherein the board has a nail pull resistance of at least about 72 lb-f according to ASTM 473-10, method B.

11. A gypsum board comprising:
a set gypsum core disposed between two cover sheets, the core formed from a slurry comprising stucco, water, and at least one uncooked non-substituted starch having a cold water viscosity at 10% of solids of from about 5 centipoise to about 50 centipoise when the viscosity is measured by a BROOKFIELD® viscometer method at 25° C.

12. The gypsum board of claim 11 , wherein the uncooked non-substituted starch has a viscosity of from about 300 BU to about 875 BU when the viscosity is measured by putting the starch in a slurry with water at a starch concentration of 15% solids, and using a VISCOGRAPH® instrument set at 75 rpm and 700 cmg, where the starch is heated from 25° C. to 95° C. at a rate of 3° C./minute, the slurry is held at 95° C. for ten minutes, and the starch is cooled to 50° C. at a rate of −3° C./minute.

13. The gypsum board of claim 11 , wherein the uncooked non-substituted starch has a cold water viscosity of about 1 centipoise to about 20 centipoise, the uncooked non-substituted starch is acid-modified, and the board has a density of from about 16 pcf to about 35 pcf.

Assignees

• United States Gypsum Co

Inventors

• Sang Yijun
• Christ Brian J

Classifications

• C04B24/38 Primary

  Polysaccharides or derivatives thereof {(C04B24/243 takes precedence)} · CPC title

• C04B28/145

  Calcium sulfate hemi-hydrate with a specific crystal form · CPC title

• C04B2111/0062

  Gypsum-paper board like materials · CPC title

• B28B11/243

  Setting, e.g. drying, dehydrating or firing ceramic articles (B28B11/242 takes precedence) · CPC title

• C04B22/16

  containing phosphorus in the anion, e.g. phosphates · CPC title