Adhesive having structural integrity and insulative properties
View Patent ↗An adhesive composition that provides improved structural integrity and insulative properties when applied to a substrate is provided. The adhesive composition includes an emulsion-based polymer, a plurality of microspheres; and optionally, water and plasticizer.
1. An article comprising a first substrate, a second substrate, and an adhesive composition interposed between the two substrates comprising:
(a) about 50 to about 99.9 weight percent, on a dry weight basis, of an emulsion-based polymer selected from the group consisting of vinyl acetate ethylene dispersion, polyvinyl acetate, polyvinyl acetate polyvinyl alcohol, dextrin stabilized polyvinyl acetate, polyvinyl acetate copolymers, vinyl acetate-ethylene copolymers, vinylacrylic, styrene acrylic, acrylic, styrene butyl rubber, polyurethane and mixtures thereof;
(b) about 0.1 to about 10 weight percent, on a dry weight basis, of a plurality of expandable microspheres;
(c) water; and
(d) optionally, plasticizer and/or preservative;
wherein the volume of the microspheres is greater than 200% in the dry adhesive upon expanding the microsphere.
2. The article of claim 1 wherein the first and the second substrate are selected from the group consisting of fiberboard, corrugated board, solid bleached boards, kraft paper, coated paper or oriented polypropylene film.
3. The article of claim 2 wherein the first and the second substrate are haft paper or coated paper.
4. The article of claim 2 wherein the boards and papers comprise a portion of recycled fiber.
5. The article of claim 1 , wherein the emulsion-based polymer is selected from the group consisting of vinyl acetate ethylene dispersion, polyvinyl acetate.
6. The article of claim 1 , wherein the plurality of microspheres are present in an amount of from about 0.5 wt % to about 5 wt %, based on the total (wet) weight of the adhesive.
7. The article of claim 6 , wherein the microspheres are expandable polymeric microspheres.
8. The article of claim 1 , wherein the adhesive further comprises a crosslinker, filler, pigment, dye, stabilizer, rheology modifier, polyvinyl alcohol, humectant and the mixtures thereof.
9. The article of claim 1 , wherein the adhesive further comprises an accelerator that is a multivalent water-soluble salt.
10. The article of claim 9 , wherein the accelerator is selected from the group consisting of aluminum nitrate, zirconium acetate, ammonium zirconyl carbonate and mixtures thereof.
11. The article of claim 1 , which is selected from the group consisting of a cup, food container, case, carton, bag, box, lid, envelope, wrap or clamshell.