Abstract: Mold- and moisture-resistant gypsum boards and methods for making them are disclosed. The boards comprise a gypsum core overlayed with facing sheets (e.g., multi-ply paper). One or preferably both of these sheets is impregnated with a thermoset resin (e.g., a phenol-formaldehyde resin) in an amount effective to (i) allow water vapor passage through the facing sheet when the thermoset resin is in its uncured state and (ii) provide mold and moisture resistance to the facing sheet when the thermoset resin is in its cured state. Advantageously, the method of manufacturing such gypsum boards requires little or no modification of existing manufacturing lines, due to the ability of the thermoset resin to cure during the normal gypsum core drying process, without significantly interfering with this process.

Abstract: An improved resole resin for producing filter media, e.g., paper, especially useful for automotive applications comprising a bisphenol-modified phenol-formaldehyde resin prepared using an amine catalyst.