| abstract |
A two part joint compound which sets by hydration of calcium sulfate hemihydrate to gypsum and is clay-free. One part includes an in-situ acidic acrylate copolymer thickener (i.e., an associative thickener) with the calcium sulfate hemihydrate, along with a non-calcium bearing phosphate set preventer. The first part contains water, but remains unset for at least 175 days. The second part includes a set initiator compound having a cation with a log K value greater than calcium ions. The second part is mixed with the first part when setting is desired. |