Patent ID: 8568632
Filing Date: 2013-10-29
Classification: B82Y,C08J,Y10T

Abstract:
1. A method of manufacturing a rigid foam board consisting essentially of: incorporating nano-particle nucleating agents into a polymer melt consisting of polystyrene, said nano-particle nucleating agents being selected from the group consisting of nanosheets of graphite, intercalated graphites and expanded graphites and having a particle size in at least one dimension of less than 100 nanometers; incorporating a blowing agent into the polymer melt under a first pressure and at a first temperature; extruding the polymer melt under a second pressure and at a second temperature, the second pressure and second temperature being sufficient to allow the polymer melt to expand and form a foam board having a solid foam structure; and cooling the foam board, said foam board having an average cell size between 60 μm and 500 μm and having a cell size distribution, wherein the average cell size is decreased by incorporation of the nano-particle nucleating agents, wherein said foam board comprises at least 90% closed cells, having an average cell wall thickness between 0.2 and 1 μm; an average strut diameter between 4 and 8 μm; a cell orientation between 1 and 1.5; and a foam density between 20 and 50 kg/m