Surface enhancing coating for gypsum-containing floor underlayments

摘要

A coating for preparing a floor underlayment to receive an adhesive includes a water-soluble, latex polymer, a defoamer and a dual-function surface enhancing agent. The surface enhancing agent includes a set accelerator that also functions to cross link the adhesive, hardening the surface of the underlayment using at least two mechanisms. One embodiment of the invention is a dry mixture that forms a coating when added to water. The dry mixture includes from about 10% to about 50% of the redispersible polymer by weight based on the mixture, from about 50% to about 90% of the surface enhancing agent and from about 0.15% to about 0.25% of the defoamer by weight based on the mixture. Other embodiments describe a liquid coating formed by adding from about 1 to about 8 pails water to 1 part of the dry mixture on a volumc basisby volume based on the mixture.