An
emulsion comprising water as the continuous phase, a
wax as the discontinuous phase, an emulsifier and a
preservative having the general structure:wherein R1 can be a heterocycle containing
nitrogen and
sulfur, such as thiazolyl, isothiazolyl, or thiadiazolyl, which can optionally be substituted with C1–C6
alkyl; R2 can be
hydrogen or C1–C6
alkyl, specifically
hydrogen; n is 0, 1, 2, or 3; each instance of R3 can independently be
hydrogen, C1–C6
alkyl, phenoxy, C1–C6 alkoxy, halo, amino, C1–C6 alkylamino, di C1–C6 alkyl amino, imidazolyl, thiazolyl, isothiazolyl, thiadiazolyl, thienyl, furyl, pyrryl, naphthyl, phenyl, halophenyl, C1–C6 alkyl phenyl, or C1–C6 alkoxyphenyl. The
preservative may be added to the
emulsion after the
emulsion is formed. The emulsion can be incorporated into a
gypsum product such as
gypsum board or
gypsum wood
fiber board. The gypsum product may be made by forming a
slurry containing gypsum, water, and the emulsion into a
solid product. A method for improving the
water resistance of a lignocellulosic composite product prepared by mixing lignocellulosic material with a binder to form a mixture and solidifying the mixture in a selected configuration to form the composite product may include adding to the mixture an emulsion as described above.