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US 12,534,408 B2Granted
Mechanical properties of waterproofed gypsum boards with polydimethylsiloxanes
AssigneeKnauf Gips KG
InventorsHans Wintrich, Janos Lotz, Lothar Scheller, Simon Gröninger
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Abstract
A waterproofed gypsum board and associated method are provided, featuring the use of a mixture of magnesium oxide and a gypsum crystal modifier for improving the resistance to sagging of the waterproofed gypsum board, in particular, in moist and warm climatic conditions.
Claims13
A waterproofed gypsum board, comprising:
- the gypsum board is waterproofed by means of at least one polysiloxane and includes magnesium oxide as a catalyst for the polymerisation of the at least one polysiloxane;
- the gypsum board being formed from a gypsum slurry which includes a calcium sulfate and a gypsum crystal modifier;
- wherein the gypsum crystal modifier is effective during the production of the gypsum board in the rehydration from hemihydrate to dihydrate;
- wherein the crystal modifier enhances the sag resistance of the gypsum board;
- wherein the gypsum crystal modifier includes at least one bivalent heavy metal salt which is selected from a group consisting of chlorides, hydroxides, oxides or combinations thereof;
- and wherein the content of the gypsum crystal modifier is between 0.01 and 0.3% by weight, in relation to the mass of the calcium sulfate in the gypsum slurry.
3 more elements
A waterproofed gypsum board, comprising:
- the gypsum board is waterproofed by means of at least one polysiloxane and includes magnesium oxide as a catalyst for the polymerisation of the at least one polysiloxane;
- the gypsum board being formed from a gypsum slurry including a calcium sulfate and a gypsum crystal modifier;
- wherein the gypsum crystal modifier is effective during the production of the gypsum board in the rehydration from hemihydrate to dihydrate;
- wherein the crystal modifier enhances the sag resistance of the gypsum board;
- wherein the gypsum crystal modifier includes at least one metal silicate;
- wherein the at least one metal silicate is a potassium silicate and belongs to the class of condensed silicates;
- and wherein the content of the gypsum crystal modifier is 0.3% by weight, in relation to the mass of the calcium sulfate in the gypsum slurry.
4 more elements
A waterproofed gypsum board, comprising:
- the gypsum board is waterproofed by means of at least one polysiloxane and includes magnesium oxide as a catalyst for the polymerisation of the at least one polysiloxane;
- the gypsum board being formed from a gypsum slurry which includes a calcium sulfate and a gypsum crystal modifier;
- wherein the gypsum crystal modifier is effective during the production of the gypsum board in the rehydration from hemihydrate to dihydrate;
- wherein the crystal modifier enhances the sag resistance of the gypsum board;
- wherein the gypsum crystal modifier includes copper sulfate pentahydrate;
- wherein the content of the polysiloxane is 0.28% by weight, in relation to the mass of the calcium sulfate in the gypsum slurry;
- wherein the content of the magnesium oxide is 0.15% by weight, in relation to the mass of the calcium sulfate in the gypsum slurry;
- wherein the content of the copper sulfate is 0.05% by weight, in relation to the mass of the calcium sulfate in the gypsum slurry.
5 more elements
Dependencies are inferred from the claim text.