Composite panel having noncombustible polymer matrix core

Abstract

A composite panel structure of a polymer matrix cote sandwiched by metal layers is described. The polymer matrix comprises 1-30 wt % fluoropolymer and 70-99 wt % of a flame retardant mineral. The fluoropolymer may be polyvinylidene fluoride (PVDF) with a high limiting oxygen index, which confers fire resistance properties to the polymer matrix and the composite panel structure. The composite panel structure may be used on the exterior of buildings and may fulfill building code requirements for the polymer matrix core being noncombustible as determined by ASTM E136 and CAN/ULC S114 compliance.

1 - 22 . (canceled) 
     
     
         23 . A building siding or cladding material haying a composite panel structure, comprising:
 a polymer core sandwiched by first and second metal layers, the polymer core comprising:   1-30 wt % fluoropolymer, and   70-99 wt % flame retardant mineral, each relative to the total weight of the polymer core,   wherein the polymer core is noncombustible as determined by ASTM E136 compliance.   
     
     
         24 . The building siding or cladding material of  claim 23 , wherein the fluoropolymer is polyvinylidene fluoride. 
     
     
         25 . The building siding or cladding material of  claim 24 , wherein the polyvinylidene fluoride has a limiting oxygen index of at least 90. 
     
     
         26 . The building siding or cladding material of  claim 23 , wherein the polymer core is monolithic, being a continuous solid with no pores, holes, or air bubbles, and
 wherein the polymer core is not penetrated by rocks or discs.   
     
     
         27 . The building siding or cladding material of  claim 23 , wherein the fluoropolymer has a melting point in a range of 100-190° C. 
     
     
         28 . The building siding or cladding material of  claim 23 , wherein the flame retardant mineral is aluminum hydroxide in the form of particles having a mean particle diameter in a range of 20-150 μm. 
     
     
         29 . A building siding or cladding comprising the building siding or cladding material of  claim 23 . 
     
     
         30 . A building siding or cladding material haying a composite panel structure, comprising:
 a polymer matrix core sandwiched by first and second metal layers, the polymer matrix core comprising:   1-24 wt % polyvinylidene fluoride having a limiting oxygen index of at least 90, and   76-99 wt % aluminum hydroxide, each relative to the total weight of the polymer matrix core,   wherein at least 97 wt % of the polymer matrix core is polyvinylidene fluoride and aluminum hydroxide.   
     
     
         31 . The building siding or cladding material of  claim 30 , wherein the polymer matrix core is noncombustible as determined by ASTM E136 compliance. 
     
     
         32 . The building siding or cladding material of  claim 30 , wherein the polymer matrix core is noncombustible as determined by CAN/ULC S114 compliance. 
     
     
         33 . The building siding or cladding material of  claim 30 , wherein the polymer matrix core is monolithic, being a continuous solid with no pores, holes, or air bubbles, and
 wherein the polymer matrix core is not penetrated by rods or discs.   
     
     
         34 . The building siding or cladding material of  claim 30 , wherein the polyvinylidene fluoride has a melting point in a range of 100-190° C. 
     
     
         35 . The building; siding or cladding material of  claim 30 , wherein the aluminum hydroxide is in the form of particles with a mean particle diameter in a range of 20-150 μm. 
     
     
         36 . A building siding or cladding, comprising the building siding or cladding material of  claim 30 . 
     
     
         37 . A method of making a building siding or cladding material, the method comprising:
 melt-mixing polyvinylidene fluoride with aluminum hydroxide to form a polymer matrix; and   shaping the polymer matrix between inner surfaces of first and second metal layers to form a polymer matrix core sandwiched between the first and second metal layers,   wherein the polymer matrix core comprises:   1-24 wt % polyvinylidene fluoride having a limiting oxygen index of at least 90, and   76-99 wt % aluminum hydroxide, each relative to the total weight of the polymer matrix core, and   wherein at least 97 wt % of the polymer matrix core is polyvinylidene fluoride and aluminum hydroxide.   
     
     
         38 . The method of  claim 37 , wherein the shaping comprises at least one manufacturing method selected from the group consisting of casting, forming, machining, and joining of two or more pieces. 
     
     
         39 . The method of  claim 37 , wherein the shaping comprises extruding the polymer matrix. 
     
     
         40 . The method of  claim 39 , wherein the shaping further comprises transferring the extruded polymer matrix to a gap between a pair of laminating rolls on a calendaring device, the laminating rolls forming the first and second metal layers. 
     
     
         41 . The method of  claim 37 , wherein the shaping comprises injection molding. 
     
     
         42 . The method of  claim 37 , wherein the polymer matrix is substantially free of stearic acid. 
     
     
         43 . The method of  claim 37 , wherein the melt-mixing is performed at a temperature in a range of 100-250° C.