Adhesive and sealant sheet material and method

Claim 1

A continuous method of preparing a low cost sheet material adapted for use as a substrate on which to cast sealants or adhesives, comprising: providing a source of a highly calendered, smooth grade kraft paper in sheet form; moving the kraft paper sheet to a first coating station where a coating of a resin composition consisting essentially of an elastomer modified vinyl polymer is applied to one major surface area of the kraft paper sheet; reversing the direction of travel of the kraft paper sheet and moving it to a second coating station where a coating of said resin composition is applied to the other major surface of the kraft paper sheet; passing the thusly coated sheet through a first drying station to dry the resin composition coatings; moving the dried resin composition coated kraft paper sheet to a third coating station where a film of a silicone release agent is applied to one of the dried resin composition coatings; passing the silicone release agent coated sheet through a second drying station to dry and cure the film of the silicone release agent; moving the kraft paper sheet to a fourth coating station and applying a film of a silicone release agent to the other dried resin composition coating; passing the sheet through said second drying station to dry and cure the film of silicone release agent applied at said fourth coating station; and forming the thusly multiple coated kraft paper sheet into a roll.