Light-weight gypsum board with improved strength and method for making same

Patent metadata

Field	Value
Publication number	US-2016229748-A1
Application number	US-201415022247-A
Country	US
Kind code	A1
Filing date	Sep 5, 2014
Priority date	Sep 17, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

Method for making light-weight gypsum board with enhanced compressive strength by addition of dispersants. Wallboards made by use of a gypsum-based composition comprising a ketone resin as dispersant and a foaming agent.

First claim

1 .- 14 . (canceled)

15 . A slurry comprising gypsum, a surfactant foam and a ketone resin, wherein the ketone resin is a condensation product of at least
(I) a ketone. (II) a formaldehyde, and (III) a compound with at least one group selected from the group consisting of phosphono, sulfite, sulphino, sulpho, sulphamido, sulphoxy, sulphoalkyloxy, sulphinoalkyloxy, phosphonooxy groups and salts of each thereof.

16 . The slurry of claim 15 , wherein the mole ratio I/II/III is 1/2 to 3/0.33 to 1.

17 . The slurry of claim 15 , wherein the ketone resin is the condensation product of cyclohexanone, formaldehyde, and sulfite.

18 . The slurry of claim 15 , wherein the ketone resin is present from 0.01 to 1 weight-%, based on the weight of gypsum in the slurry.

19 . The slurry of claim 18 , wherein the ketone resin is provided as 15 to 60 weight % solids of an aqueous solution.

20 . The slurry of claim 15 , wherein the surfactant foam is prepared from an aqueous surfactant solution comprising a linear or branched fatty alkyl sulfate, linear or branched fatty alkyl ether sulfate, hydrotrope or a mixture thereof.

21 . The slurry of claim 15 , wherein the gypsum further comprises clay.

22 . The slurry of claim 21 , wherein the clay is a swellable clay.

23 . A wallboard comprising a set gypsum core that is produced from the slurry according to claim 15 .

24 . The wallboard of claim 23 with a dry weight density of 0.45-1.0 kg/m 3 .

25 . The wallboard of claim 23 with a dry weight density of 0.50-0.80 kg/m 3 .

26 . The wallboard of claim 24 , wherein the set gypsum core comprises a ketone resin.

27 . The wallboard of claim 26 , wherein the ketone resin is present in the set gypsum core in a range of 0.01 to 0.5 weight-% of the solid condensation product, based on the weight of gypsum.

28 . A method of making a gypsum wallboard of claim 23 comprising the steps of:
preparing a foam from a surfactant;
preparing an aqueous slurry of gypsum containing ketone resin in the range from 0.01 to 1.0 weight-%, based on the weight of gypsum;
mixing the foam into the aqueous slurry of gypsum;
sandwiching the slurry between cover sheets to form wallboard;
cutting the gypsum wallboard after the gypsum slurry has sufficiently hardened; and
drying the gypsum wallboard.

29 . A wallboard comprising a set gypsum core produced from a slurry comprising gypsum, a foam and a ketone resin, wherein the ketone resin is a condensation product of at least
(I) a ketone. (II) a formaldehyde, and (III) a compound with at least one group selected from the group consisting of phosphono, sulfite, sulphino, sulpho, sulphamido, sulphoxy, sulphoalkyloxy, sulphinoalkyloxy, phosphonooxy groups and salts of each thereof, wherein the mole ratio I/II/III is 1/2 to 3/0.33 to 1, and the ketone resin is present from 0.01 to 1 weight-%, based on the weight of gypsum in the slurry, said wallboard having a dry weight density of 0.50-0.80 kg/m 3 .

30 . The wallboard of claim 29 , wherein the ketone resin is the condensation product of cyclohexanone, formaldehyde, and sulfite.

31 . The wallboard of claim 29 , wherein the surfactant foam is prepared from an aqueous surfactant solution comprising a linear or branched fatty alkyl sulfate, linear or branched fatty alkyl ether sulfate, hydrotrope or a mixture thereof, and the gypsum further comprises a swellable clay.

Assignees

• Basf Se
• Basf Ag

Inventors

• Gehrig Uwe
• Dengler Joachim
• Schinabeck Michael
• Pichler Martin
• Gädt Torben
• Loges Stephanie

Classifications

• C04B2111/0062

  Gypsum-paper board like materials · CPC title

• C04B28/14 Primary

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

• C04B41/5307

  Removal of physically bonded water, e.g. drying of hardened concrete (E04B1/7007 takes precedence) · CPC title

• C04B24/30 Primary

  Condensation polymers of aldehydes or ketones · CPC title

• C04B38/10

  by using foaming agents (C04B38/02 takes precedence){or by using mechanical means, e.g. adding preformed foam} · CPC title