Patent ID: 7063771

Claim:
An embossed insulating paperboard comprising: at least one layer of cellulose fibers, at least some of the cellulose fibers in said at least one layer being crosslinked cellulosic fibers present in an amount from 25% to 100% of said at least one layer, said paperboard being sufficiently insulating to provide a hot water ΔT across said paperboard of at least 0.70° C.±2.30° C. per 0.1 mm of caliper, said paperboard having a density of less than 0.5 g/cc, and a basis weight of from 200 gsm to 500 gsm, said paperboard being embossed with a surface pattern to reduce the effective surface area of the paperboard, the caliper of said paperboard being greater than or equal to 0.5 mm.