Compositions and methods for reducing the surface temperature of composite articles
A composition includes an infrared reflective additive having one or more infrared reflective colorants and a thermally emissive filler. The infrared reflective additive can be melt processed in a polymeric matrix.
1 . An article comprising:
(a) a wood plastic composite core having a peripheral surface; and
(b) a capstock bonded to at least a portion of the peripheral surface of the wood plastic composite core, wherein the capstock comprises a polymer matrix with an infrared reflective additive blended therein, the infrared reflective additive comprising one or more infrared reflective colorants and a thermally emissive filler; wherein:
the capstock has an L* value according to CIE L*a*b* color scale coordinates of less than 50; and
the capstock has a heat build-up according to HBU (OIR) of less than 60° F. and/or a heat build-up according to HBU ASTM-D4803 of less than 60° F.
2 . The article according to claim 1 , wherein the capstock further comprises one or more infrared transparent colorants.
3 . The article according to claim 2 , wherein one of the one or more infrared transparent colorants is black.
4 . The article according to claim 1 , wherein the thermally emissive filler is boron nitride.
5 . The article according to claim 1 , wherein the polymer matrix comprises a polyethylene, a polypropylene, a polyolefin copolymer, a functionalized polyolefin, a polystyrene, a polystyrene copolymer, a polyacrylate, a polymethacrylate, a polyester, a polyvinylchloride, a fluoropolymer, a polyamide, a polyether imide, a polyphenylene sulfide, a polysulfone, a polyacetal, a polycarbonate, a polyphenylene oxide, a polyurethane, a thermoplastic elastomer, an epoxy, an alkyd, a melamine, a phenolic, a urea, a vinyl ester, or combinations thereof.
6 . The article according to claim 1 , wherein the polymer matrix comprises a crosslinkable polymer.
7 . The article according to claim 1 , wherein the capstock further comprises an organic or inorganic filler.
8 . The article according to claim 1 , wherein the capstock further comprises a white colorant comprising titanium dioxide and/or zirconium dioxide.
9 . The article according to claim 8 , wherein the white colorant comprises titanium dioxide.
10 . The article according to claim 1 , wherein the article is a decking product, a fencing product, a railing product, a roofing product, or a siding product.
11 . The article according to claim 1 , wherein: the thermally emissive filler is boron nitride; and the capstock further comprises one or more infrared transparent colorants.
12 . The article according to claim 11 , wherein the polymer matrix comprises a polyethylene, a polypropylene, a polyolefin copolymer, a functionalized polyolefin, a polystyrene, a polystyrene copolymer, a polyacrylate, a polymethacrylate, a polyester, a polyvinylchloride, a fluoropolymer, a polyamide, a polyether imide, a polyphenylene sulfide, a polysulfone, a polyacetal, a polycarbonate, a polyphenylene oxide, a polyurethane, a thermoplastic elastomer, an epoxy, an alkyd, a melamine, a phenolic, a urea, a vinyl ester, or combinations thereof.
13 . The article according to claim 11 , wherein: one of the one or more infrared transparent colorants is black; and/or the capstock further comprises a white colorant comprising titanium dioxide and/or zirconium dioxide.
14 . The article according to claim 1 , wherein the infrared reflective colorant comprises Cr 2 O 3 ; Fe 2 O 3 ; NiTiO 3 ; CoTiO 3 ; FeTiO 3 ; a mixed metal oxide containing iron and chromium; a mixed metal oxide containing tin, titanium, and zinc; or any combination thereof.
15 . The article according to claim 14 , wherein the capstock further comprises one or more infrared transparent colorants.
16 . The article according to claim 14 , wherein the thermally emissive filler is boron nitride.
17 . The article according to claim 14 , wherein the capstock further comprises an organic or inorganic filler.
18 . The article according to claim 14 , wherein the capstock further comprises a white colorant comprising titanium dioxide and/or zirconium dioxide.
19 . The article according to claim 18 , wherein the white colorant comprises titanium dioxide.
20 . The article according to claim 14 , wherein the article is a decking product, a fencing product, a railing product, a roofing product, or a siding product.