Copper containing infrared reflective pigment compositions
View Patent ↗Pigment compositions are described that advantageously increase total solar reflectance. Also described are methods of making pigment compositions. The pigment compositions can contain copper oxide; copper antimony oxides, copper bismuth oxides, or combinations thereof; and alkaline earth metal oxides, early-transition metal oxides, post-transition metal oxides, metalloid (semi-metal) oxides, rare-earth metal oxides, or combinations thereof.
1. A colored pigment composition comprising a mixed metal oxide pigment having a crystal structure that includes two or more types of metal atoms and oxygen atoms, and is of the formula:
CuO.(A) x .(B) y ,
where x=0.01-2; y=0.01-2; A is antimony oxides, bismuth oxides, or combinations thereof; B is oxides of Mg, Ca, Sr, Ba, Ti, Zr, Zn, Al, Si, B, Ce, or combinations thereof wherein the pigment composition exhibits an average reflection of about 20% or less for light having a wavelength between 380 nm and 780 nm, and the pigment composition exhibits an average reflection of about 20% or more for light having a wavelength between 780 nm and 2500 nm and wherein the pigment composition is in a powder form having an average particle size of about 0.2 μm or more and about 15 μm or less.
2. The pigment composition of claim 1 , wherein A is Sb 2 O 3 , Sb 2 O 5 , Bi 2 O 3 , or combinations thereof.
3. The pigment composition of claim 1 , wherein B is MgO, CaO, SrO, TiO 2 , ZrO 2 , ZnO, SiO 2 , B 2 O 3 , CeO 2 , or combinations thereof.
4. The pigment composition of claim 1 , wherein the pigment composition exhibits an average reflection of about 30% or more for light having a wavelength between 1,300 and 1,600 nm.
5. The pigment composition of claim 1 , wherein the oxides of Mg, Ca, Sr, Ba, Ti, Zr, Zn, Al, Si, B, Ce, or combinations thereof contain metal cations comprising a valence shell with only empty (d 0 ), full-filled d-orbitals (d 10 ), or no d-orbital electrons.
6. The pigment composition of claim 1 , wherein the pigment composition exhibits a total solar reflectance of about 15% of more.