Two-component binder for exterior fiberboard

Abstract

A two-component binder system for exterior grade fiberboard and other products, the first component comprising a stable aqueous solution of about 10 to 15 weight percent urea, about 30 to 40 weight percent formaldehyde, about 25 to 40 weight percent water, about 15 to 25 weight percent melamine, about 0.4 to 1.0 weight percent of a buffering agent which maintains the pH at about 6.5 to 7.0 and optionally up to about 6 weight percent of an alkanol of 1 to 6 carbon atoms, the solution having a viscosity when formed of less than about 60 cps and a viscosity after about 7 days of less than about 1000 cps. The second component is a solution comprising about 35 to 55 weight percent urea, about 45 to 65 percent water and optionally up to about 4 weight percent of a catalyst which promotes the reaction of urea, formaldehyde and melamine. The two components may be admixed at room temperature in a ratio of about 3 to 5 parts of the first component to one part of the second component to form the binder.

Dependencies are inferred from the claim text.