Thermoplastic single ply protective covering

1. A method of making a single ply protective covering, the method comprising:

providing a single ply thermoplastic roofing membrane;

coating the single ply thermoplastic roofing membrane on its bottom surface with a 1-50 mil layer of a pressure sensitive adhesive mixture consisting essentially of polyisobutylene and at least one polymer comprising conjugated diene monomers.

2. The method of claim 1 further comprising embedding a scrim in the single ply thermoplastic roofing membrane.

3. The method of claim 1 further comprising annealing an adhesive adsorbing layer to the bottom surface of the single ply thermoplastic roofing membrane before the coating of pressure sensitive adhesive is applied.

4. The method of claim 1 wherein the single ply thermoplastic roofing membrane includes a thermoplastic polyolefin.

5. The method of claim 1 wherein the pressure sensitive adhesive mixture contains up to about 3 wt. % of a thickener, thinner or a viscosity modifier.

6. The method of claim 1 wherein the pressure sensitive adhesive mixture contains up to about 5 wt. % of an antioxidant, rubber tackifier, a plasticizer, anti-flow additive, a UV stabilizer or a mixture thereof.

7. The method of claim 1 wherein the pressure sensitive adhesive mixture contains up to about 25 wt. % filler such as CaCO 3 or TiO 2 or carbon black.

8. The method of claim 1 , wherein the polyisobutylene has a number average molecular weight from approximately 40,000 to 400,000.

9. The method of claim 1 , wherein the free surface of the pressure sensitive adhesive is covered with kraft paper or a silicone treated release sheet and packaged as a roll.

10. The method of claim 1 , wherein the conjugated diene monomers are selected from the group consisting of 1,3-butadiene, 2-methyl-1,3-butadiene(isoprene), 2,3-dimethyl-1,3-butadiene, 1-phenyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene and chloroprene, 2,3-di-tert-butyl-1,3-butadiene, 1,3,5-hexatriene, and 1,3,5,7-octatetraene.

11. The method of claim 1 wherein the polyisobutylene and the at least one polymer comprising conjugated diene monomers are present in the pressure sensitive adhesive in equal parts.

12. The method of claim 1 further comprising:

mixing the polyisobutylene and the at least one polymer comprising conjugated diene monomers with heat into a spreadable pressure sensitive adhesive.

13. A method of installing a single ply thermoplastic roofing membrane on a roof, the method comprising the steps of:

(a) providing a single ply thermoplastic roofing membrane coated on its bottom surface with a 1-50 mil layer of a pressure sensitive adhesive mixture consisting essentially of polyisobutylene and at least one polymer comprising conjugated diene monomers;

(b) cutting the single ply thermoplastic roofing membrane to a selected size;

(c) positioning the single ply thermoplastic roofing membrane on a portion of a roof; and

(d) bonding the membrane to the roof.

14. The method of claim 13 wherein the pressure sensitive adhesive is covered with kraft paper or a silicone treated release sheet, and the method includes the steps of removing the kraft paper or silicone release sheet prior to bonding the membrane to the roof.

15. The method of claim 14 wherein the single ply thermoplastic roofing membrane is provided in the form of a roll.

16. The method of claim 13 further comprising heat sealing any seams in the resulting bonded roofing membrane.

17. The method of claim 13 wherein the single ply thermoplastic roofing membrane includes an adhesive absorbing layer annealed to the bottom surface of the membrane between the membrane and the pressure sensitive adhesive.

18. The method of claim 13 wherein the pressure sensitive adhesive mixture contains a thickener, a viscosity modifier, an antioxidant, a rubber tackifier, a plasticizer, an anti-flow additive, a UV stabilizer, a filler or mixtures thereof.

19. The method of claim 13 wherein the polyisobutylene and the at least one polymer comprising conjugated diene monomers are present in the pressure sensitive adhesive in equal parts.