Boron-free anti-sagging additive for gypsum building materials

Patent metadata

Field	Value
Publication number	US-2021380484-A1
Application number	US-201817287011-A
Country	US
Kind code	A1
Filing date	Oct 26, 2018
Priority date	Oct 26, 2018
Publication date	Dec 9, 2021
Grant date	—

Abstract

The invention concerns an anti-sagging additive for producing shaped gypsum articles. The additive is boron-free and comprises L-tartaric acid and/or L-tartrates and a pH-enhancing compound.

First claim

1 . An anti-sagging additive for producing shaped gypsum articles, comprising L-tartaric acid and/or L-tartrates and a pH-enhancing compound but no boron-containing compounds.

2 . The anti-sagging additive according to claim 1 , wherein the pH-enhancing compound is a cement.

3 . The anti-sagging additive according to claim 1 , wherein a ratio of an amount of L-tartaric acid or L-tartrate to an amount of pH-enhancing compound is from 1:1 to 1:10.

4 - 5 . (canceled)

6 . A shaped gypsum article produced at least from a slurry formed from calcined gypsum, water, and an anti-sagging additive, wherein the anti-sagging additive comprises L-tartaric acid and/or L-tartrates and a pH-enhancing compound but no boron compounds.

7 . A method for producing a shaped gypsum articles comprising steps of mixing of calcined gypsum with water and an additive, wherein the additive comprises L-tartaric acid and/or L-tartrates and a pH-enhancing compound, and forming the shaped gypsum article.

8 . The anti-sagging additive according to claim 3 , wherein the ratio of the amount of the L-tartaric acid or the L-tartrate to the amount of the pH-enhancing compound is from 1:2 to 1:5.

9 . The shaped gypsum article according to claim 6 , wherein the L-tartaric acid and/or the L-tartrates is/are contained in a mass of from 0.001 to 0.1% by weight in relation to a mass of the calcined gypsum.

10 . The shaped gypsum article according to claim 9 , wherein the L-tartaric acid and/or the L-tartrates is/are contained in the mass of from 0.01 to 0.05% by weight in relation to the mass of the calcined gypsum.

11 . The shaped gypsum article according to claim 6 , wherein the pH-enhancing compound is contained in a quantity of from 0.05 to 0.5% by weight in relation to a mass of the calcined gypsum.

12 . The shaped gypsum article according to claim 11 , wherein the pH-enhancing compound is contained in the quantity of from 0.08 to 0.25% by weight in relation to the mass of the calcined gypsum.

13 . The shaped gypsum article according to claim 6 , wherein the shaped gypsum article is a gypsum board.

14 . The method according to claim 7 , wherein the shaped gypsum article is a gypsum board.

15 . The method according to claim 7 , wherein the method comprises the step of drying the shaped gypsum article.

Assignees

• Knauf Gips Kg

Inventors

• Pietschmann Bernd
• Steinbauer Michael
• Weigand David
• Kohler Verena
• Köhler Juliane

Classifications

• C04B2103/0094

  Agents for altering or buffering the pH; Ingredients characterised by their pH · CPC title

• C04B2111/0062

  Gypsum-paper board like materials · CPC title

• C04B2111/10

  Compositions or ingredients thereof characterised by the absence or the very low content of a specific material · CPC title

• C04B2103/0082

  Segregation-preventing agents; Sedimentation-preventing agents · CPC title

• C04B28/14 Primary

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