Pressure-sensitive adhesives including expandable graphite

1. A composite comprising:

i. a polymeric sheet;

ii. a layer of pressure-sensitive adhesive, where the layer of pressure-sensitive adhesive includes first and second planar surfaces, and where the first planar surface of the pressure-sensitive adhesive layer is fixedly attached to the polymeric sheet;

iii. concentrated region of expandable graphite, where the concentrated region of expandable graphite is at or proximate to the second planar surface of the pressure-sensitive adhesive, and where the concentrated region of expandable graphite is discontinuous to thereby allow the pressure-sensitive adhesive to be exposed; and

iv. a release liner or film removably attached to the second planar surface of the pressure-sensitive adhesive.

2. The composite of claim 1 , where said layer of pressure-sensitive adhesive includes a planar region that is substantially devoid of expandable graphite.

3. The composite of claim 1 , where said concentrated planar region of expandable graphite has a thickness of from about 10 μm to about 3 mm.

4. The composite of claim 1 , where said concentrated planar region of expandable graphite is proximate to the release film relative to the polymeric sheet.

5. The composite of claim 1 , where the polymeric sheet includes a thermoplastic sheet.

6. The composite of claim 1 , where the polymeric sheet includes a thermoset sheet.

7. The composite of claim 1 , where the concentrated region of expandable graphite is formed by dropping expandable graphite on to the second planar surface of the pressure-sensitive adhesive.

8. The composite of claim 7 , where the expandable graphite is at least partially embedded within the pressure-sensitive adhesive layer.

9. The composite of claim 8 , where the concentrated region of expandable graphite is partially dispersed within said pressure-sensitive adhesive layer to form a concentration gradient whereby the concentration of the expandable graphite within the pressure-sensitive adhesive layer moves from a region of maximum concentration proximate to the second planar surface of the adhesive layer to a region of minimum concentration at the first planar surface of the adhesive layer.

10. A composite prepared by a process comprising:

i. providing a layer of pressure-sensitive adhesive; and

ii. dropping expandable graphite on to the layer of pressure-sensitive adhesive to thereby form a composite comprising

a polymeric sheet;

b. the layer of pressure-sensitive adhesive, where the layer of pressure sensitive adhesive includes first and second planar surfaces, and where the first planar surface of the pressure-sensitive adhesive layer is fixedly attached to the polymeric sheet;

c. the dropped expandable graphite in a concentrated region, where the concentrated region of expandable graphite is at or proximate to the second planar surface of the pressure-sensitive adhesive, and where the concentrated region of expandable graphite is discontinuous to thereby allow the pressure-sensitive adhesive to be exposed; and

d. a release linear or film removably attached to the second planar surface of the pressure-sensitive adhesive.

11. The composite of claim 10 , where adhesive forces from the pressure-sensitive adhesive fixedly secure the polymeric sheet thereby sandwiching the expandable graphite between the polymeric sheet and the pressure-sensitive adhesive.