Abstract: Disclosed are formaldehyde-free, thermally-curable, alkaline, aqueous binder compositions, curable to formaldehyde-free, water-insoluble thermoset polyester resins, and uses thereof as binders for non-woven fibers and fiber materials.

Abstract: The prevent invention relates to improved fiber glass compositions and to methods of preparing such compositions using an improved resin binder. The resin binder comprises an aqueous solution of a resole resin, a catalyst comprising an ammonia salt of an aryl sulfonic acid, and optional binder modifiers. It has been found that the use of ammonium aryl sulfonate salts in resin binder compositions, as in the present invention, provides an enhanced cure rate and also enables manufacture of a fiber glass composition exhibiting enhanced uncured storage properties, increased thermal stability, and reduced corrosiveness to metals.