Disalt as robust primary surfactant for calcium sulfate mixtures containing recycled gypsum
AssigneesBASF SE, Saint-Gobain Placo
InventorsUwe Gehrig, Fabian Niedermair, Joachim Dengler, Georg Daxenberger, Hamouda Jaffel
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Abstract
The present invention relates to a gypsum composition comprising recycled gypsum and a foam former comprising at least one alpha-sulfo fatty acid disalt, to a process for production thereof and to an article comprising the gypsum composition of the invention. The present invention further relates to the use of a foam former comprising at least one alpha-sulfo fatty acid disalt for reducing the wet density of an aqueous gypsum composition having a recycled gypsum content of at least 0.5% by weight.
Claims20
An aqueous gypsum composition, comprising:
- at least 40.0% by weight of gypsum, and
- at least 0.002% by weight of a foam former comprising at least one alpha-sulfo fatty acid disalt, each weight percentage based on the total weight of the aqueous gypsum composition, and
- wherein the gypsum has a recycled gypsum content of at least 0.5% by weight, based on the total weight of gypsum.
A process for producing an aqueous gypsum composition, comprising:
- providing a foam comprising a foam former, the foam former comprising at least one alpha-sulfo fatty acid disalt;
- providing a composition comprising water and gypsum, and optionally comprising additives;
- and
- allowing shear forces to act on the composition with addition of the foam;
- wherein the gypsum has a recycled gypsum content of at least 0.5% by weight, based on the total weight of gypsum.
A method of using a foam former comprising at least one alpha-sulfo fatty acid disalt, the method comprising:
- reducing the wet density of an aqueous gypsum composition,
- wherein the aqueous gypsum composition has a recycled gypsum content of at least 0.5% by weight, based on the total weight of gypsum.
A process for producing a gypsum board comprising the steps of
- providing a foam comprising a foam former, the foam former comprising at least one alpha-sulfo fatty acid disalt;
- providing a composition comprising water and gypsum, and optionally comprising additives;
- allowing shear forces to act on the composition with addition of the foam;
- and
- drying the obtained composition thermally;
- wherein the gypsum has a recycled gypsum content of at least 0.5% by weight, based on the total weight of gypsum.
A gypsum board obtained by thermally drying an aqueous gypsum composition comprising:
- at least 40.0% by weight of gypsum, and
- at least 0.002% by weight of a foam former comprising at least one alpha-sulfo fatty acid disalt, each weight percentage based on the total weight of the aqueous gypsum composition, and
- wherein the gypsum has a recycled gypsum content of at least 0.5% by weight, based on the total weight of gypsum.
Dependencies are inferred from the claim text.