Patent ID: 8597426

Claim:
A building panel comprising: a panel body with core voids comprising: a calcium sulfate dihydrate matrix; a dispersant component selected from the group consisting of a comb-branched polymer having polyether side chains, naphthalene sulfonate-formaldehyde condensate, melamine sulfonate-formaldehyde condensate and mixtures of two or more thereof; a foaming agent; and a polycondensation component comprising: a first polycondensation repeating unit having a polyether side chain and one of the group consisting of an aromatic sub-unit and a heteroaromatic sub-unit; a second polycondensation repeating unit having a OP(OH) 2 group and one of the group consisting of an aromatic sub-unit and a heteroaromatic sub-unit; and a third polycondensation repeating unit having one of the group consisting of an aromatic sub-unit and a heteroaromatic sub-unit; wherein said second polycondensation repeating unit and said third polycondensation repeating unit differ exclusively in that the OP(OH) 2 groups of said second polycondensation repeating unit are replaced by H in said third polycondensation repeating unit, and said third polycondensation repeating unit is not the same as said first polycondensation repeating unit; and wherein the weight ratio of the dispersant component to the polycondensation component ranges from 1:99 to 75:25.