Article comprising an adhesion promoter coating

Abstract

It is desired to find a new class of adhesion promoters to adhere the granules to the asphalt. Generally, the application is directed to an article comprising a substrate and a coating on the substrate, wherein the coating comprises a polyolefin. The substrate may be a roofing granule. In certain embodiments, the polyolefin is a chemically modified polyolefin. In some embodiments, the coating comprises a photocatalytic material.

1 . An article comprising
 a substrate; and   an adhesion promoter coating on the substrate,   
     wherein the coating comprises a polyolefin. 
   
   
       2 . The article of  claim 1  wherein the substrate is a roofing granule. 
   
   
       3 . The article of  claim 1  wherein the polyolefin is a chemically modified polyolefin. 
   
   
       4 . The article of  claim 3  wherein the polyolefin is modified with a chemically reactive group comprising amines, epoxides, anhydrides, hydroxyls, thiols, isocyanates, acids, halides, or esters. 
   
   
       5 . The article of  claim 1  wherein the coating comprises a mixture of polyolefins. 
   
   
       6 . The article of  claim 5  wherein the mixture of polyolefins comprise at least one chemically modified polyolefin. 
   
   
       7 . The article of  claim 6  wherein the chemically reactive group comprising amines, epoxides, anhydrides, hydroxyls, thiols, isocyanates, acids, halides, or esters. 
   
   
       8 . The article of  claim 4  wherein the chemically modified polyolefin is modified with maleic anhydride. 
   
   
       9 . The article of  claim 1  wherein the polyolefin is polypropylene. 
   
   
       10 . The article of  claim 2  wherein the roofing granule comprises a photocatalytic material. 
   
   
       11 . The article of  claim 10  wherein the photocatalytic material comprises TiO 2 , ZnO, WO 3 , SnO 2 , CaTiO 3 , Fe 2 O 3 , MoO 3 , Nb 2 O 5 , Ti x Zr( 1-x )O 2 , SiC, SrTiO 3 , CdS, GaP, InP, GaAs, BaTiO 3 , KNbO 3 , Ta 2 O 5 , Bi 2 O 3 , NiO, Cu 2 O, SiO 2 , MoS 2 , InPb, RuO 2 , CeO 2 , Ti(OH) 4 , or combinations thereof. 
   
   
       12 . The article of  claim 11  wherein the photocatalytic material comprises crystalline anatase TiO 2 , crystalline rutile TiO 2 , crystalline ZnO or combinations thereof. 
   
   
       13 . The article of  claim 10  wherein the photocatalytic material is doped with a dopant. 
   
   
       14 . The article of  claim 13  wherein the dopant is C, N, S, F, Pt, Pd, Au, Ag, Os, Rh, RuO 2 , Nb, Cu, Sn, Ni, Fe, or combinations thereof. 
   
   
       15 . The article of  claim 1  wherein the article has a reflectivity of at least about 20% at substantially all points in the wavelength range between 770 and 2500 nm. 
   
   
       16 . An article comprising
 a first coated substrate, comprising first substrate and an adhesion promoter coating comprising a polyolefin on the first substrate;   a second substrate,   
     wherein the first coated substrate and the second substrate are attached and the coating on the first substrate is between the first substrate and the second substrate. 
   
   
       17 . The article of  claim 16  wherein the first coated substrate is a roofing granule. 
   
   
       18 . The article of  claim 16  wherein the second substrate comprises an asphalt layer. 
   
   
       19 . The article of  claim 16  wherein the polyolefin is a chemically modified polyolefin. 
   
   
       20 . The article of  claim 19  wherein the polyolefin is modified with a chemically reactive group comprising amines, epoxides, anhydrides, hydroxyls, thiols, isocyanates, acids, halides, or esters. 
   
   
       21 . The article of  claim 16  wherein the coating comprises a mixture of polyolefins. 
   
   
       22 . The article of  claim 21  wherein the mixture of polyolefins comprise at least one chemically modified polyolefin. 
   
   
       23 . The article of  claim 22  wherein the chemically reactive group comprising amines, epoxides, anhydrides, hydroxyls, thiols, isocyanates, acids, halides, or esters. 
   
   
       24 . The article of  claim 19  wherein the chemically modified polyolefin as modified with maleic anhydride. 
   
   
       25 . The article of  claim 16  wherein the polyolefin is polypropylene. 
   
   
       26 . The article of  claim 17  wherein the roofing granule comprises a photocatalytic material. 
   
   
       27 . The article of  claim 26  wherein the photocatalytic material comprises TiO 2 , ZnO, WO 3 , SnO 2 , CaTiO 3 , Fe 2 O 3 , MoO 3 , Nb 2 O 5 , Ti x Zr( 1-x )O 2 , SiC, SrTiO 3 , CdS, GaP, InP, GaAs, BaTiO 3 , KNbO 3 , Ta 2 O 5 , Bi 2 O 3 , NiO, Cu 2 O, SiO 2 , MoS 2 , InPb, RuO 2 , CeO 2 , Ti(OH) 4 , or combinations thereof. 
   
   
       28 . The article of  claim 27  wherein the photocatalytic material comprises crystalline anatase TiO 2 , crystalline rutile TiO 2 , crystalline ZnO or combinations thereof. 
   
   
       29 . The article of  claim 26  wherein the photocatalytic material is doped with a dopant. 
   
   
       30 . The article of  claim 29  wherein the dopant is C, N, S, F, Pt, Pd, Au, Ag, Os, Rh, RuO 2 , Nb, Cu, Sn, Ni, Fe, or combinations thereof. 
   
   
       31 . The article of  claim 16  wherein the article has a reflectivity of at least about 20% at substantially all points in the wavelength range between 770 and 2500 nm.