Adhesive having insulative properties
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 a paper 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 4 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;
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 the insulating component, to an exposed surface of the applied adhesive composition to form the paper insulative sheet;
e. exposing the paper insulative sheet to a radiation energy sufficient to expand the expandable microspheres while leaving at least 10% moisture content in the applied adhesive composition; and
f. exposing the paper insulative sheet to an additional radiation energy to fully set the applied adhesive composition.
2. The method of making the paper insulative sheet of claim 1 , wherein the radiation energy sufficient to expand the expandable microspheres is infrared energy.
3. The method of making the paper insulative sheet of claim 1 , wherein the radiation energy sufficient to expand the expandable microspheres expands at least a majority of the expandable microspheres in the applied adhesive composition.