Fire-retardant oriented strand board
A two-part flame-retardant, a flame-retardant oriented strand (OSB) and method for forming a flame-retardant OSB is provided. The two-part flame-retardant composition includes an aqueous solution containing a water-soluble flame-retardant and a flame-retardant powder that is incorporated into an oriented strand board without substantially affecting the mechanical properties of the oriented strand board. The method includes applying the aqueous solution containing a water-soluble flame-retardant to an oriented strand board furnish and applying a flame-retardant powder to the wetted furnish, without requiring an additional drying step.
1. A two-part flame-retardant for oriented strand board comprising:
an aqueous solution comprising a solvent and a water-soluble flame-retardant comprising an amine phosphoric acid salt, a dicyandiamide-formaldehyde phosphoric acid salt, or a combination thereof, wherein the aqueous solution comprises at least about 40 wt. % of the water-soluble flame retardant; and
a solid flame-retardant powder having a median particle size (d50) of about 1 μm to about 1000 μm.
2. The two-part flame-retardant of claim 1 , wherein the water-soluble flame-retardant is
an amine phosphoric acid salt, which is a polyethylene amine phosphoric acid salt, or a dicyandiamide-formaldehyde phosphoric acid salt, or combinations thereof.
3. The two-part flame-retardant of claim 2 , wherein the polyethylene amine phosphoric acid salt is a reaction product of tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA),
hexaethyleneheptamine (HEHA), higher molecular weight polyethylene amine product such as Polyamine B, or mixtures thereof, with phosphoric acid.
4. The two-part flame-retardant of claim 1 , wherein the solid flame-retardant powder has a median particle size (d50) of from about 2 μm to about 850 μm.
5. The two-part flame-retardant of claim 1 , wherein the solid flame-retardant powder comprises
a boric acid,
borax,
disodium octaborate tetrahydrate (DOT),
guanylurea phosphate (GUP),
an ammonium polyphosphate (APP), or
combinations thereof.
6. The two-part flame-retardant of claim 5 , wherein the solid flame-retardant powder comprises
a 1:1 wt. % blend of boric acid and borax, and/or
a 1:1 wt. % blend of boric acid and disodium octaborate tetrahydrate (DOT).
7. The two-part flame-retardant of claim 5 , wherein the ammonium polyphosphate (APP) is ammonium polyphosphate phase 2.
8. A kit comprising a two-part flame-retardant as defined in claim 1 .