Abstract: A water based, cold seal, cohesive coating for bonding one or more substrates together to form a flexible package to contain an article, especially useful for snack food packaging. The cohesive coating includes about 25% to about 90% by weight of a natural rubber latex emulsion, about 10% to about 75% by weight of a non-self-crosslinking acrylic emulsion, about 0.01% to about 10% by weight water, and one or more ingredient selected from an anti-foam agent, ammonia, a surfactant, an anti-blocking agent, an inert filler, and a conditioning agent, so that in combination the components total 100% by weight of the composition. The use of a non-self-crosslinking acrylic emulsion provides an improved cold seal cohesive that may be employed with current high temperature converting systems and provides improved adhesion to substrates, enhanced cohesion to itself, reduced blocking and avoids seal deadening.

Abstract: The present invention provides a waterbase self seal adhesive system utilizing a self seal adhesive containing no natural rubber. The self seal adhesive system is comprised of a transfer (front) adhesive disposed on a transfer (front) web and an anchor (back) adhesive disposed on an anchor (back) web with the two adhesives forming the seal for the package. The self seal adhesives bond to themselves when pressure is applied to close or seal the packaging material. In one embodiment, when peeled apart, the adhesive transfers from one substrate of the package to the other substrate of the package to enable opening of the package and thereafter prevents resealing of the package. In another embodiment, when peeled apart, the adhesive splits, adhesively fails from either or both the front web or the back web, or destroys one or both of the substrates of the package. In either embodiment, primers and release coatings may also be used to enhance performance of the self seal adhesive.