Adhesive having insulative properties
View Patent ↗An improved adhesive composition having increased insulative properties is provided. The adhesive composition having improved insulative properties includes a starch component; an alkaline component; sodium tetraborate; water; and a plurality of expandable microspheres. Products having improved insulation capabilities and methods of making the products having improved insulation capabilities are also provided. The present adhesive and products including the adhesive is environmentally friendly.
1. A method of making an insulative sheet, comprising the steps of:
a. providing a substantially planar paper sheet having a first side and a second side, said first side having any type of surface to accommodate an insulating component;
b. preparing an adhesive composition by
combining a high amylose starch component that has an amylose content greater than 50%, an unmodified starch component, an alkaline component, sodium tetraborate, water, and about 0.5 to about 5 wet basis weight percent of a plurality of expandable microspheres to form a starch mixture; wherein the expandable microspheres has (i) a T exp , the temperature at which the expandable microspheres begin to expand and (ii) a T max , the temperature at which the expandable microspheres have reached maximum expansion;
c. applying said adhesive composition to said surface of said first side of said substantially planar paper sheet to form a sheet with an applied adhesive composition and heating the applied adhesive composition to a gelatinization temperature of from about 138 to about 156° F.;
d. applying a second substantially planar paper sheet having a first side and a second side, said first side having any type of surface to accommodate an insulating component, to the top surface of the adhesive composition to form a laminate;
e. then heating said laminate to a first temperature of from about 180 to about 210° F. to expand the expandable microspheres; and
f. heating said sheet with said applied adhesive composition to a second temperature of from about 250 to about 285° F. sufficient to fully cure said adhesive composition.
2. The method of claim 1 , wherein said step of applying said adhesive composition to said first side of said substantially planar paper sheet comprises applying said adhesive composition such that said plurality of expandable microspheres are applied in a configuration selected from the group consisting of dots, stripes, waves, checkerboard patterns, any general polyhedron shapes that have substantially flat bases, cylinders, and combinations thereof.