Adhesive for insulative articles
An adhesive composition that improves structural integrity and insulative properties when applied to a cellulosic substrate is provided. The adhesive composition includes a plurality of microspheres and an emulsion-based polymer that has (i) an elastic modulus greater than 0.5 MPa in the range temperature range of 70° C. to 110° C.; (ii) an absolute log(E)/T slope of less than 0.05 in the range temperature range of 70° C. to 110° C.; and (iii) a tan d value less than 0.6 at 90° C.
1. A waterborne-based adhesive comprising:
(a) a water-based polymer prepared by emulsion polymerization;
(b) a plurality of expandable microspheres; and
(c) optionally, an additive;
wherein the water-based polymer has (i) an elastic modulus greater than 0.5 MPa in the range temperature range of 70° C. to 110° C.; (ii) an absolute log(E)/T slope of less than 0.05 in the range temperature range of 70° C. to 110° C.; and (iii) a tan d value less than 0.6 at 90° C.
2. The waterborne-based adhesive of claim 1 , wherein the water-based polymer has (i) modulus of 5 MPa at 85° C. to 100° C.
3. The waterborne-based adhesive of claim 1 , wherein the water-based polymer is selected from the group consisting of 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.
4. The waterborne-based adhesive of claim 1 , wherein the expandable microspheres have a hydrocarbon core and a polyacrylonitrile shell.
5. The waterborne-based adhesive of claim 1 , wherein the expandable microspheres begin to expand at a temperature of about 80° C. to about 100° C.
6. The waterborne-based adhesive of claim 1 , wherein the expandable microspheres have a maximum expansion temperature of about 120° C. to about 130° C.
7. The waterborne-based adhesive of claim 1 , further comprising a crosslinker, defoamer, preservative, surfactant, rheology modifier, filler, pigment, dye, stabilizer, polyvinyl alcohol, humectant, and mixtures thereof.
8. The waterborne-based adhesive of claim 1 , wherein the additive is selected from the group consisting of tackifiers, plasticizers, crosslinker, and mixtures thereof.
9. The waterborne-based adhesive of claim 8 , wherein the crosslinker is selected from the group consisting of aluminum nitrate, zirconium acetate, ammonium zirconyl carbonate and mixtures thereof.
10. The waterborne-based adhesive composition of claim 1 , wherein the adhesive further comprises an accelerator that is a multivalent water-soluble salt.
11. The waterborne-based adhesive composition of claim 10 , wherein the multivalent water-soluble salt is selected from the group consisting of aluminum nitrate, zirconium acetate, ammonium zirconyl carbonate and mixtures thereof.
12. A process for forming an article comprising the steps of:
(a) preparing a composition comprising:
(1) a water-based polymer prepared by emulsion polymerization that has (i) an elastic modulus greater than 0.5 MPa in the range temperature range of 70° C. to 110° C.; (ii) an absolute log(E)/T slope of less than 0.05 in the range temperature range of 70° C. to 110° C.; and (iii) a tan d value less than 0.6 at 90° C.; and
(2) a plurality of expandable microspheres;
(b) applying the composition onto a substrate, which is a paper, paperboard or wood;
(c) drying the composition to substantially remove the water; and
(d) expanding the composition.
13. The process of claim 12 , wherein steps (c) and (d) are simultaneously combined.
14. The process of claim 12 , wherein the composition is applied in a pattern.
15. The process of claim 14 , wherein the pattern is a series of dots, stripes, waves, checkerboards, or a polyhedron shape that have substantially a flat base.
16. An article comprising a cellulosic substrate and a composition comprising:
(a) a water-based polymer prepared by emulsion polymerization that has (i) an elastic modulus greater than 0.5 MPa in the range temperature range of 70° C. to 110° C.; (ii) an absolute log(E)/T slope of less than 0.05 in the range temperature range of 70° C. to 110° C.; and (iii) a tan d value less than 0.6 at 90° C.; and
(b) a plurality of expandable microspheres.
17. The article of claim 16 , wherein the water-based polymer is selected from the group consisting of 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.
18. The article of claim 17 , wherein the cellulosic substrate is a fiberboard, corrugated board, solid bleached boards, kraft paper or coated paper.
19. The article of claim 16 is a multilayer substrate.
20. The multilayer substrate of claim 19 is a cup, food container, case, carton, bag, box, lids, envelope, wrap or clamshell.