Corrugated fiberboard

Claim 1

from about 5 to 75 weight percent of at least one polyvinyl polymer selected from the group consisting of: polyvinyl acetate, partially hydrolyzed derivatives of polyvinyl acetate, and substantially fully hydrolyzed polyvinyl alcohol, and each such polyvinyl polymer being further characterized by having a molecular weight such that an aqueous solution or colloidal dispersion (including latices, emulsions, etc.) thereof can be prepared initially which, at a polymer concentration of about 4 weight percent, has a viscosity of from about 5 to 125 centipoises, C. as a liner, a cellulosic sheet member having a thickness of from about 5 to 20 thousandths of an inch and having a basis weight of from about 33 to 120 pounds per 1,000 sq. ft., D. as a bonding composition, a water-resistant adhesive system employing at least one polymer selected from the group consisting of said aminoplast containing phenol-aldehyde resin systems, said polyvinyl polymers, urea-formaldehyde resins and phenol-formaldehyde resins, E. said corrugated medium sheet member being positioned adjacent said liner sheet member and being bonded thereto at positions of mutual contact therebetween by said bonding composition, and F. such resulting construction having been subjected to a temperature of from about 160* to 235* C. for times of from about 0.5 seconds to 5 minutes.