Near infrared transmitting copper oxide nanoparticles
AssigneeToyota Motor Engineering & Manufacturing North America, Inc.
InventorsSongtao Wu, Debasish Banerjee, Krishna Gunugunuri
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Abstract
A black IR reflective or transmissive pigment from which LiDAR responsive black coatings can be formed where the pigment displays a Blackness My value similar to non-IR reflective carbon black. The CuO particles display small crystallites of less than 18 nm and an (−111)/(111) reflectance intensity ratio of less than 1.2. A method of forming the CuO particles includes precipitation of CuCO3 or CuCO3/Cu(OH)2 using an alkali carbonate as a precipitant and calcining the precipitate at about 300° C. to about 400° C.
Claims22
A black pigment with near IR transmitting and/or reflecting properties, the black pigment comprising
- a plurality of CuO crystallites with a maximum dimension of 18 nm or less, and a (−111)/(111) intensity ratio of less than 1.2, wherein the black pigment displays a band gap of 1.7 eV or less.
A coating composition, comprising:
- a fluid vehicle;
- and a black pigment with near IR transmitting and/or reflecting properties suspended in the fluid vehicle, wherein the black pigment comprises CuO crystallites with a maximum dimension of 18 nm or less, and a (−111)/(111) intensity ratio of less than 1.2, and wherein the coating composition displays a band gap of −1.7 eV or less.
A method for forming near IR reflecting or transmitting CuO crystallites, comprising:
- providing a solution or a suspension comprising a water-soluble Cu(II) salt;
- adding a precipitant solution comprising an alkali metal carbonate with the solution or the suspension to form a precipitate comprising CuCO3;
- washing the precipitate with water;
- isolating the precipitate;
- and
- calcining the precipitate at a temperature between about 300 and about 400° C. to form the near IR reflecting or transmitting CuO crystallites, wherein the CuO crystallites have a maximum dimension of 18 nm or less, and a (−111)/(111) intensity ratio less than 1.2, wherein the CuO crystallites display a band gap of 1.7 eV or less.
Dependencies are inferred from the claim text.