Class a fire-retardant polyisocyanurate foam boards and process for making
AssigneeDdp Specialty Electronic Materials US, LLC
InventorsKali Ananth Suryadevara, Steve Black, Dan Youmans, Kyoung Moo Koh, Mark Rickard
Life of this patent
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Abstract
A faced polyisocyanurate foam board comprising a halogen-free foam made from a halogen-free foam formulation comprising isocyanate, polyol, and phosphorus-containing flame retardant, and 1.06 to 1.66 kg/m3 (30 to 47 g/ft3) of glass fiber distributed in the foam throughout the thickness of the board; wherein the polyisocyanurate foam board has a trimer content of 11 to 19.5 weight percent, at least 0.1 weight percent phosphorous, and as measured by ASTM E84, a Flame Spread Index of 0 to 25 and a maximum Smoke Development Index of 450 or less.
Claims17
A polyisocyanurate foam board having a length, width, and thickness, and having a facesheet on both major outer surfaces, the foam board comprising:
- a) a halogen-free foam made from a halogen-free foam formulation comprising isocyanate, polyol, and phosphorus-containing flame retardant;
- and
- b) 1.24 to 1.59 kg/m3 (35 to 45 g/ft3) of glass fiber distributed in the foam throughout the thickness of the board;
- wherein the polyisocyanurate foam board has a trimer content of 11 to 19.5 weight percent based on the said halogen-free foam, at least 0.1 weight percent phosphorous based on the said halogen-free foam, and wherein said board has, as measured by ASTM E84, a Flame Spread Index of 0 to 25 and a maximum Smoke Development Index of 450 or less.
A process for making a polyisocyanurate foam board comprising the steps of:
- a) making a flowable halogen-free foam formulation comprising isocyanate and polyol, and phosphorus-containing flame retardant,
- wherein the NCO Index is 225 to 480, and the flowable halogen-free foam formulation has at least 0.11 weight percent phosphorus;
- b) contacting the flowable halogen-free foam formulation with 1.24 to 1.59 kg/m3 (35 to 45 g/ft3) of an expandable web of glass fiber;
- c) pressing the flowable foam formulation into the web of glass fiber to form a board precursor,
- d) allowing the flowable foam formulation in the board precursor to expand into a foam in the presence of the web of glass fibers, wherein foam formulation separates and distributes the glass fibers in the web throughout the foam, and further cure to form the polyisocyanurate foam board,
- wherein the polyisocyanurate foam board has, as measured by ASTM E84, a Flame Spread Index of 0 to 25 and a maximum Smoke Development Index of 450 or less.
Dependencies are inferred from the claim text.