Patent ID: 7993483
Filing Date: 2011-08-09
Classification: B31F,C08L,C09J

Abstract:
1. A method of preparing starch based adhesive for producing wax free corrugated paperboard without moisture resistant coatings comprising the steps of: a) heating a solution of polyvinyl alcohol (PVA) hydrolyzed from about 87% to about 89% to a temperature in the range from about 180° F. to 220° F. and holding said solution at said temperature for at least about 60 minutes; b) cooling said solution of polyvinyl alcohol to a temperature in the range of about 90° F. to about 100° F.; and c) mixing said cooled PVA solution with about an equal amount by weight of a aldehyde ketone resin solution having solids in the range of about 50 to 70 wt % to produce a PVA additive composition; and, d) combining said PVA additive in a minor amount with an adhesive starch batch of a minor amount of modified starch and a major amount of pearl starch, wherein the combined said PVA additive and said adhesive starch batch is heated to a gel condition to produce an improved adhesive.